#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll maxn=100000, maxx=1000000001;
typedef vector<ll> vi;
typedef pair<ll,ll> pi;
typedef pair<ll,pi> pii;
typedef vector<pi> vii;
#define fi first
#define sc second
#define mp make_pair
#define pb push_back
ll k,n;
string buf,bufx;
ll x, y;
vi dict;
ll sum[2*maxn+10];
ll gege;
int main(){
ios_base::sync_with_stdio(false);
gege=0;
cin >> k >> n;
if (k==1){
for(int i=0;i<n;i++){
cin >> buf >> x >> bufx >> y;
if (buf==bufx) {
gege+= labs(x-y);
}
else {
dict.pb(x); dict.pb(y);
}
}
sort(dict.begin(),dict.end());
for(int i=0;i<dict.size();i++){
sum[i]=(i==0?0:sum[i-1])+dict[i];
}
ll ans = LONG_LONG_MAX;
for(int i=0;i<dict.size();i++){
ans =min(ans,dict[i]*(i+1)-sum[i]+sum[dict.size()-1]-sum[i]-dict[i]*(ll(dict.size())-i-1));
//cout << dict[i] <<" " << dict[i]*(i+1)-sum[i]+sum[dict.size()-1]-sum[i]-dict[i]*(ll(dict.size())-i-1) << "\n";
}
if (ans==LONG_LONG_MAX) ans=0;
cout << ans+gege+dict.size()/2 << "\n";
return 0;
}
else{
vii dic;
for(int i=0;i<n;i++){
cin >> buf >> x >> bufx >> y;
if (buf==bufx){
gege+=labs(x-y);
}
else{
dic.pb(mp(x,y));
dict.pb(x); dict.pb(y);
}
}
sort(dict.begin(),dict.end());
ll ans = LONG_LONG_MAX, semen;
for(int i=0;i<dict.size();i++){
ll l = 0, r = 1000000001;
ll mid1,mid2,mid3,semen1,semen2,semen3;
while(l<r){
mid1=l+(r-l)/3; mid2=(l+(r-l)*2/3); mid3 = (l+r)/2;
semen1=0,semen2=0,semen3=0;
for(int k=0;k<dic.size();k++){
semen1+=min(labs(dic[k].fi-dict[i])+labs(dic[k].sc-dict[i]),labs(dic[k].fi-mid1)+labs(dic[k].sc-mid1));
semen2+=min(labs(dic[k].fi-dict[i])+labs(dic[k].sc-dict[i]),labs(dic[k].fi-mid2)+labs(dic[k].sc-mid2));
semen3+=min(labs(dic[k].fi-dict[i])+labs(dic[k].sc-dict[i]),labs(dic[k].fi-mid3)+labs(dic[k].sc-mid3));
}
if (semen1>semen3&&semen2>semen3){
l=mid1; r=mid2;
}
else if (semen1>semen3&&semen2<semen3){
l=mid1;
}
else{
r=mid2;
}
ans = min(ans,min(semen1,min(semen3,semen2)));
// cout << dict[l] << " " << dict[r]<<"\n";
// cout << l << " dan " << r << " jadinya " << ans << "\n";
}
semen = 0;
for(int k=0;k<dic.size();k++){
semen+=min(labs(dic[k].fi-dict[i])+labs(dic[k].sc-dict[i]),labs(dic[k].fi-l)+labs(dic[k].sc-l));
}
ans=min(semen,ans);
}
if (ans==LONG_LONG_MAX) ans=0;
cout << ans + gege+dict.size()/2 << "\n";
}
}
