#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for (int i=a;i<n;i++)
#define per(i,a,n) for (int i=n-1;i>=a;i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
typedef vector<int> VI;
typedef long long ll;
typedef pair<int,int> PII;
typedef double db;
mt19937 mrand(random_device{}());
const ll mod=1000000007;
const ll mod2=998244353;
int rnd(int x) { return mrand() % x;}
ll powmod(ll a,ll b) {ll res=1;a%=mod; assert(b>=0); for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
// head
const int N=101000;
int k,n,m,s[N],t[N],a[N],b[N],p[N];
char ss[N],tt[N];
ll pf[N],sf[N];
struct ds{
int med;
ll sm;
ds() { sm=0; }
multiset<int> L,R;
void add(int x,int y) {
if (x>y) swap(x,y);
if (SZ(L)==0) {
sm=y-x;
L.insert(x);
R.insert(y);
med=x;
return;
}
(x<=med?L:R).insert(x);
(y<=med?L:R).insert(y);
while (SZ(L)>SZ(R)) {
R.insert(*prev(L.end()));
L.erase(prev(L.end()));
}
while (SZ(L)<SZ(R)) {
L.insert(*R.begin());
R.erase(R.begin());
}
int nm=*prev(L.end());
sm+=abs(nm-x)+abs(nm-y);
if (med>nm) sm+=abs(med-nm)*2;
med=nm;
}
};
int main() {
scanf("%d%d",&k,&n);
rep(i,1,n+1) scanf("\n%c %d %c %d",ss+i,s+i,tt+i,t+i);
ll ans=1e18,same=0;
rep(i,1,n+1) {
if (ss[i]==tt[i]) {
same+=abs(s[i]-t[i]);
}
else a[++m]=s[i],b[m]=t[i];
}
assert(m!=0);
rep(i,1,m+1) p[i]=i;
sort(p+1,p+1+m,[&](int i,int j) {
return a[i]+b[i]<a[j]+b[j];
});
ds pref;
pref.sm=0;
rep(i,1,m+1) {
pref.add(a[p[i]],b[p[i]]);
pf[i]=pref.sm;
}
ds suff;
suff.sm=0;
per(i,1,m+1) {
suff.add(a[p[i]],b[p[i]]);
sf[i]=suff.sm;
}
/*rep(i,1,m+1) {
printf("%lld %lld\n",pf[i],sf[i]);
}*/
rep(i,1,m+1) ans=min(ans,pf[i]+sf[i+1]);
if (k==2) printf("%lld",ans+same+m);
else printf("%lld\n",pf[m]+same+m);
}
/*
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
1 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
*/
