/*input
1 5
B0A4
B1B3
A5B7
B2A6
B1A7
*/
#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<long long, null_type, less_equal<long long>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
#pragma GCC optimize("unroll-loops,no-stack-protector")
//order_of_key #of elements less than x
// find_by_order kth element
using ll = long long;
using ld = long double;
using pii = pair<ll,ll>;
#define f first
#define s second
#define pb push_back
#define REP(i,n) for(int i=0;i<n;i++)
#define REP1(i,n) for(ll i=1;i<=n;i++)
#define FILL(n,x) memset(n,x,sizeof(n))
#define ALL(_a) _a.begin(),_a.end()
#define sz(x) (int)x.size()
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
const ll INF64=4e18;
const int INF=0x3f3f3f3f;
const ll MOD=1e9+7;
const ld PI=acos(-1);
const ld eps=1e-9;
#define lowb(x) x&(-x)
#define MNTO(x,y) x=min(x,(__typeof__(x))y)
#define MXTO(x,y) x=max(x,(__typeof__(x))y)
#define MP make_pair
ll mult(ll a,ll b){
return ((a%MOD)*(b%MOD))%MOD;
}
ll mypow(ll a,ll b){
if(b<=0) return 1;
ll res=1LL;
while(b){
if(b&1) res=(res*a)%MOD;
a=(a*a)%MOD;
b>>=1;
}
return res;
}
const ll maxn=1e5+5;
const ll maxlg=__lg(maxn)+2;
#define int ll
ll pv[maxn],suff[maxn];
bool cmp(pii a,pii b){
return a.f+a.s<b.f+b.s;
}
int32_t main(){
ios::sync_with_stdio(false),cin.tie(0);
int k,n;
cin>>k>>n;
ll ans=0;
vector<pii> v;
REP(i,n){
char a,b;
int x,y;
cin>>a>>x>>b>>y;
if(a==b) ans+=abs(x-y);
else v.pb({x,y}),ans++;
}
sort(ALL(v),cmp);
n=sz(v);
if(!sz(v)){
cout<<ans;
return 0;
}
priority_queue<int> mn,mx;
ll mns=0,mxs=0;
REP(i,n){
if(v[i].f>v[i].s) swap(v[i].f,v[i].s);
if(!sz(mx)){
mn.push(v[i].f),mns+=v[i].f;
mx.push(-v[i].s),mxs+=v[i].s;
pv[i]=mxs-mns;
continue;
}
int mnn=mn.top(),mxx=-mx.top();
if(v[i].s<=mnn){
mn.pop();
mns-=mnn;
mn.push(v[i].f),mns+=v[i].f;
mn.push(v[i].s),mns+=v[i].s;
mx.push(-mnn),mxs+=mnn;
}
else if(v[i].f>=mxx){
mx.pop();
mxs-=mxx;
mx.push(-v[i].f),mxs+=v[i].f;
mx.push(-v[i].s),mxs+=v[i].s;
mn.push(mxx),mns+=mxx;
}
else{
mx.push(-v[i].s),mxs+=v[i].s;
mn.push(v[i].f),mns+=v[i].f;
}
assert(sz(mx)==sz(mn));
pv[i]=mxs-mns;
}
while(sz(mn)) mn.pop();
while(sz(mx)) mx.pop();
mns=mxs=0;
ll cur=pv[n-1];
for(int i=n-1;i>=0;i--){
if(!sz(mx)){
mn.push(v[i].f),mns+=v[i].f;
mx.push(-v[i].s),mxs+=v[i].s;
suff[i]=mxs-mns;
continue;
}
int mnn=mn.top(),mxx=-mx.top();
if(v[i].s<=mnn){
mn.pop();
mns-=mnn;
mn.push(v[i].f),mns+=v[i].f;
mn.push(v[i].s),mns+=v[i].s;
mx.push(-mnn),mxs+=mnn;
}
else if(v[i].f>=mxx){
mx.pop();
mxs-=mxx;
mx.push(-v[i].f),mxs+=v[i].f;
mx.push(-v[i].s),mxs+=v[i].s;
mn.push(mxx),mns+=mxx;
}
else{
mx.push(-v[i].s),mxs+=v[i].s;
mn.push(v[i].f),mns+=v[i].f;
}
assert(sz(mx)==sz(mn));
suff[i]=mxs-mns;
}
if(k==2) REP(i,n-1) MNTO(cur,pv[i]+suff[i+1]);
cout<<ans+cur;
}
