#include <bits/stdc++.h>
using namespace std;
#define LL long long
#define pb push_back
#define MAXN 200005
set < int > st;
vector < int > V;
int n,k,N;
int P[100000 + 5],S[100000 + 5], Q[100000 + 5], T[100000 + 5];
char inp[10];
LL gans = LLONG_MAX;
vector < int > MS[MAXN * 4 + 5];
vector < int > VMS[MAXN * 4 + 5], CA[MAXN * 4 + 5], CB[MAXN * 4 + 5];
vector < LL > PA[MAXN * 4 + 5], PB[MAXN * 4 + 5];
vector < int > TA[MAXN * 4 + 5], TB[MAXN * 4 + 5], VA[MAXN * 4 + 5], VB[MAXN * 4 + 5];
vector < LL > A[MAXN * 4 + 5], B[MAXN * 4 + 5];
int mut( int a ){
if ( a < 0 ) a = a * -1;
return a;
}
int gv( int x ){
if ( x > 1e9 + 1 ) return V.size()-1;
return lower_bound(V.begin(),V.end(),x) - V.begin();
}
void upd( int p, int s, int e, int x, int v ){
MS[p].pb(v);
if ( s == e ) return;
int m = ( s + e) >> 1;
if ( x <= m ) upd(p+p+1,s,m,x,v);
else upd(p+p+2,m+1,e,x,v);
}
void process( int p ){
st.clear();
for ( int id : MS[p] ){
st.insert(S[id] + T[id]);
}
for ( int s : st ){
VMS[p].pb(s);
PA[p].pb(0);
PB[p].pb(0);
CA[p].pb(0);
CB[p].pb(0);
}
for ( int id : MS[p] ){
int pos = lower_bound(VMS[p].begin(),VMS[p].end(),S[id] + T[id]) - VMS[p].begin();
CA[p][pos]++;
CB[p][pos]++;
PA[p][pos] += S[id];
PB[p][pos] += T[id];
}
for ( int i = 1; i < VMS[p].size(); i++ ){
CA[p][i] += CA[p][i-1];
CB[p][i] += CB[p][i-1];
PA[p][i] += PA[p][i-1];
PB[p][i] += PB[p][i-1];
}
st.clear();
for ( int id : MS[p] ){
st.insert(T[id]);
}
for ( int s : st ){
VB[p].pb(s);
TB[p].pb(0);
B[p].pb(0);
}
for ( int id : MS[p] ){
int pos = lower_bound(VB[p].begin(),VB[p].end(), T[id]) - VB[p].begin();
TB[p][pos]++;
B[p][pos] += T[id];
}
for ( int i = 1; i < VB[p].size(); i++ ){
TB[p][i] += TB[p][i-1];
B[p][i] += B[p][i-1];
}
st.clear();
for ( int id : MS[p] ){
st.insert(S[id]);
}
for ( int s : st ){
VA[p].pb(s);
TA[p].pb(0);
A[p].pb(0);
}
for ( int id : MS[p] ){
int pos = lower_bound(VA[p].begin(),VA[p].end(), S[id]) - VA[p].begin();
TA[p][pos]++;
A[p][pos] += S[id];
}
for ( int i = 1; i < VA[p].size(); i++ ){
TA[p][i] += TA[p][i-1];
A[p][i] += A[p][i-1];
}
}
void build( int p, int s, int e ){
process(p);
if ( s == e ){
return;
}
int m = ( s + e ) >> 1;
build(p+p+1,s,m);
build(p+p+2,m+1,e);
}
LL rmq_b( int p, int s, int e, int r ){
if ( s > r ) return 0;
if ( e <= r ){
int pos = upper_bound(VB[p].begin(),VB[p].end(), V[r]) - VB[p].begin() - 1;
LL sum = 0;
if ( pos >= 0 ){
sum += V[r] * 1LL * TB[p][pos] - B[p][pos];
sum = sum + sum;
}
return sum;
}
int m = ( s + e ) >> 1;
return rmq_b(p+p+1,s,m,r) + rmq_b(p+p+2,m+1,e,r);
}
LL rmq_bb( int p, int s, int e, int l, int r ){
if ( s > r || e < l ) return 0;
if ( l <= s && e <= r ){
int pos = upper_bound(VB[p].begin(),VB[p].end(), V[r]) - VB[p].begin();
LL sum = 0;
if ( pos < VB[p].size() ){
sum += B[p].back() - (pos==0?0:B[p][pos-1]);
sum -= 1LL * V[r] * (TB[p].back() - (pos==0?0:TB[p][pos-1]));
}
return sum;
}
}
LL rmq_a( int p, int s, int e, int l ){
if ( e < l ) return 0;
if ( l <= s ){
int pos = lower_bound(VA[p].begin(),VA[p].end(),V[l]) - VA[p].begin();
LL sum = 0;
if ( pos < VA[p].size() ){
sum += A[p].back() - (pos == 0 ? 0 : A[p][pos-1]) - 1LL * V[l] * (TA[p].back() - (pos==0?0:TA[p][pos-1]));
sum += sum;
}
return sum;
}
int m = ( s + e ) >> 1;
return rmq_a(p+p+1,s,m,l) + rmq_a(p+p+2,m+1,e,l);
}
LL rmq_ab( int p, int s, int e , int l, int r ){
if ( s > r || e < l ) return 0;
if ( l <= s && e <= r ){
int lim = V[l] + V[r];
LL sum = 0;
int pos = upper_bound(VMS[p].begin(),VMS[p].end(), lim) - VMS[p].begin() - 1;
if ( pos >= 0 ){
sum += PA[p][pos] - 1LL * V[l] * (CA[p][pos]);
sum = sum + sum;
}
return sum;
}
int m = ( s + e ) / 2;
return rmq_ab(p+p+1,s,m,l,r) + rmq_ab(p+p+2,m+1,e,l,r);
}
LL rmq_ba( int p, int s, int e, int l, int r ){
if ( s > r || e < l ) return 0;
if ( l <= s && e <= r ){
int lim = V[l] + V[r];
LL sum = 0;
int pos = upper_bound(VMS[p].begin(),VMS[p].end(), lim) - VMS[p].begin();
if ( pos < VMS[p].size()){
sum += 1LL * V[r] * (CB[p].back() - (pos == 0 ? 0 : CB[p][pos-1]));
sum -= PB[p].back() - (pos==0?0:PB[p][pos-1]);
}
return sum;
}
int m = ( s + e ) >> 1;
return rmq_ba(p+p+1,s,m,l,r) + rmq_ba(p+p+2,m+1,e,l,r);
}
LL solve( int p1, int p2 ){
LL ls = rmq_b(0,0,N,p1);
LL rs = rmq_a(0,0,N,p2);
LL ab = rmq_ab(0,0,N,p1,p2);
LL ba = rmq_ba(0,0,N,p1,p2) - rmq_bb(0,0,N,p1,p2);
//printf("%lld %lld %lld %lld = %d %d\n",ls,rs,ab,ba + ba,V[p1],V[p2]);
return ls + rs + ab + ba + ba;
}
void dnc( int l, int r, int optl, int optr ){
if ( l > r ) return;
int m = ( l + r ) / 2;
LL ans = LLONG_MAX;
int opt = -1;
for ( int i = optl; i <= min(m-1, optr); i++ ){
LL temp = solve(i,m);
if ( temp < ans ) ans = temp;
}
if ( ans < gans ) gans = ans;
dnc(l,m-1,optl,opt);
dnc(m+1,r,opt,optr);
}
int main(){
scanf("%d%d",&k,&n);
LL ans = 1e18, sum = 0;
for ( int i = 0; i < n; i++ ){
scanf("%s%d",&inp,&S[i]);
if ( inp[0] == 'A' ){
P[i] = 0;
} else {
P[i] = 1;
}
scanf("%s%d",&inp,&T[i]);
if ( inp[0] == 'A' ){
Q[i] = 0;
} else {
Q[i] = 1;
}
// P[i] = 0;
// Q[i] = 1;
// S[i] = i;
// T[i] = 1e9 - i;
if ( S[i] > T[i] ) swap(S[i],T[i]);
sum += T[i] - S[i];
if ( P[i] != Q[i] ){
st.insert(S[i]);
st.insert(T[i]);
sum++;
}
}
st.insert(-1);
st.insert(1e9 + 1);
for ( int s : st ) V.pb(s);
N = V.size()-1;
for ( int i = 0; i < n; i++ ){
if ( P[i] != Q[i] ){
upd(0,0,N,gv(S[i]),i);
}
}
build(0,0,N);
if ( k == 1 ){
for ( int i = 0; i <= N; i++ ){
LL temp = rmq_b(0,0,N,i) + rmq_a(0,0,N,i);
if ( temp + sum < ans ) ans = temp + sum;
}
} else {
dnc(1,N,0,N);
ans = gans + sum;
}
printf("%lld\n",ans);
return 0;
}
