#include<bits/stdc++.h>
#define ll long long
using namespace std;
int main(){
ll k,n,i,j;
cin>>k>>n;
vector<ll> s(n),t(n);
vector<char> p(n),q(n);
ll ans=0,cnt=0,pos;
for(i=0 ; i<n ; i++){
cin>>p[i]>>s[i]>>q[i]>>t[i];
if(p[i]==q[i]){
cnt++;
ans+=abs(s[i]-t[i]);
continue;
}
}
if(k==1){
ll val=1e18;
if(cnt==n) val=0;
for(i=0 ; i<n ; i++){
if(p[i]==q[i]) continue;
pos=s[i];
cnt=0;
for(j=0 ; j<n ; j++){
if(p[j]==q[j]) continue;
cnt+=abs(pos-s[j])+abs(pos-t[j])+1;
}
val=min(val,cnt);
pos=t[i];
cnt=0;
for(j=0 ; j<n ; j++){
if(p[j]==q[j]) continue;
cnt+=abs(pos-s[j])+abs(pos-t[j])+1;
}
val=min(val,cnt);
}
ans+=val;
cout<<ans<<"\n";
}
return 0;
}
