#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int maxn=1e5+5;
int k,n;
bool cmp(pair<int,int>a,pair<int,int>b){
return a.first + a.second < b.first + b.second;
}
void f(vector<pair<int,int>>v,vector<ll>&jg){
multiset<int>m1,m2;
ll sm = 0, bg = 0;
for(int i = 0;i < (int)v.size();i++){
m1.insert(v[i].first);
sm += v[i].first;
m2.insert(v[i].second);
bg += v[i].second;
while(*m1.rbegin() > *m2.begin()){
sm += *m2.begin() - *m1.rbegin();
bg += *m1.rbegin() - *m2.begin();
m1.insert(*m2.begin());
m2.insert(*m1.rbegin());
m1.erase(--m1.end());
m2.erase(*m2.begin());
}
jg.push_back(bg-sm);
}
}
int main(){
ios::sync_with_stdio(false);
cin.tie(0);
cin >> k >> n;
ll jog = 0;
vector<pair<int,int>>v;
for(int i = 1;i <= n;i++){
char p,q;
int x,y;
cin >> p >> x >> q >> y;
if(p == q) jog += abs(x-y);
else {
v.push_back({x,y});
}
}
sort(v.begin(),v.end(),cmp);
n = v.size();
vector<ll>lft,rgt;
f(v, lft);
reverse(v.begin(),v.end());
f(v,rgt);
if(k == 1){
cout<<jog + lft[n-1] + n;
return 0;
}
ll ans = lft[n-1];
for(int i = 0;i < n-1;i++){
ans = min(ans,lft[i] + rgt[n-i-2]);
// cout<<i<<' '<<lft[i]<<' '<<rgt[n-i-2]<<'\n';
}
cout<<ans + jog + n;
}
