#include<bits/stdc++.h>
#define ll long long
using namespace std;
int main(void){
ios::sync_with_stdio(0);cin.tie(0);
ll k,n,i,j;
cin>>k>>n;
vector<ll> s(n),t(n);
vector<char> p(n),q(n);
ll ans=0;
vector<pair<ll,ll>> v;
for(i=0 ; i<n ; i++){
cin>>p[i]>>s[i]>>q[i]>>t[i];
if(p[i]==q[i]) ans+=abs(s[i]-t[i]);
else{
v.push_back({s[i]+t[i],i});
ans++;
}
}
if(v.empty()){
cout<<ans<<"\n";
return 0;
}
sort(v.begin(),v.end());
auto get=[&](ll l,ll r){
if(l>r) return 0LL;
vector<ll> pts;
for(i=l ; i<=r ; i++){
pts.push_back(t[v[i].second]);
pts.push_back(s[v[i].second]);
}
sort(pts.begin(),pts.end());
ll med=pts[pts.size()/2],sum=0;
for(auto v:pts) sum+=abs(v-med);
return sum;
};
if(k==1) ans+=get(0,v.size()-1);
else{
ll sz=v.size();
ll ok=0,ng=sz-1;
ll val=get(0,sz-1);
while(ng-ok>1){
ll mid=(ng+ok)/2;
ll x=get(0,mid)+get(mid+1,sz-1);
ll y=get(0,mid+1)+get(mid+2,sz-1);
val=min(val,min(x,y));
if(x<y) ng=mid;
else ok=mid;
}
for(i=max(0LL,ok-2) ; i<=min(sz-1,ng+2) ; i++){
val=min(val,get(0,i)+get(i+1,sz-1));
}
ans+=val;
}
cout<<ans<<"\n";
return 0;
}
