#include<bits/stdc++.h>
using namespace std;
#define int long long
signed main(){
int a,b,c,d,e=0,f=0,ans=0,mii=1e10,bf,esf=0;
map<int,int>ma,en;
map<int,int>::iterator maa,maaa;
char ch1,ch2;
cin>>a>>b;
for(int i=0;i<b;i++){
cin>>ch1>>c>>ch2>>d;
if(ch1!=ch2){
if(c>d) swap(c,d);
ma[c]+=2;
ma[d]+=2;
en[d]+=1;
f+=c*2;
e-=2;
ans++;
}
ans+=abs(d-c);
}
// cout<<ans<<endl;
if(a==1){
bf=ma.begin()->first;
for(maa=ma.begin();maa!=ma.end();maa++){
f+=(maa->first-bf)*e;
e+=maa->second;
mii=min(mii,f);
bf=maa->first;
}
}
else{
bf=ma.begin()->first;
for(maa=ma.begin();maa!=ma.end();maa++){
cout<<1;
f+=(maa->first-bf)*e;
e+=maa->second;
esf+=en[maa->first];
int tempe=e,tempf=f,tempbf=maa->first;
tempe-=esf*2;
maaa=maa;
maaa++;
for(maaa=maaa;maaa!=ma.end();maaa++){
tempf+=(maaa->first-tempbf)*tempe;
tempe+=maaa->second;
tempbf=maaa->first;
mii=min(mii,tempf);
}
bf=maa->first;
}
}
cout<<mii+ans;
}
