#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
#define fi first
#define se second
const int N = 1e5+5;
int n,k,pre[N],suml = 0,sumr = 0;
priority_queue<int>pql;
priority_queue<int,vector<int>,greater<int>>pqr;
vector<pii>v;
bool cmp(pii a, pii b){
return a.fi+a.se < b.fi+b.se;
}
void add(int val){
int med = 1e9+1;
if(pql.size()) med = pql.top();
if(val <= med){
pql.push(val);
suml += val;
}
else{
pqr.push(val);
sumr += val;
}
if(pql.size() > pqr.size()+1){
int x = pql.top();
pql.pop();
pqr.push(x);
suml -= x;
sumr += x;
}
if(pqr.size() > pql.size()){
int x = pqr.top();
pqr.pop();
pql.push(x);
sumr -= x;
suml += x;
}
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cin >> k >> n;
int ans = 0;
for(int i = 1; i <= n; i++){
char p,q;
int s,t;
cin >> p >> s >> q >> t;
if(p == q) ans += abs(t-s);
else v.push_back({s,t});
}
if(v.empty()){
cout << ans;
return 0;
}
sort(v.begin(),v.end(),cmp);
ans += v.size();
if(k == 1){
for(int i = 0; i < v.size(); i++){
add(v[i].fi);
add(v[i].se);
}
ans += sumr-suml;
cout << ans;
}
else{
for(int i = 0; i < v.size(); i++){
add(v[i].fi);
add(v[i].se);
pre[i] = sumr-suml;
}
int mn = pre[v.size()-1];
while(!pql.empty()) pql.pop();
while(!pqr.empty()) pqr.pop();
suml = 0;
sumr = 0;
for(int i = v.size()-1; i >= 1; i--){
add(v[i].fi);
add(v[i].se);
mn = min(mn,pre[i-1]+sumr-suml);
}
cout << ans+mn;
}
}
