#include <bits/stdc++.h>
using namespace std;
const int Nmax = 3e5;
int n, k, len;
long long ans = 0, suml = 0, sumr = 0, pre[Nmax + 3];
vector<pair<int, int>> val;
multiset<int> up, down;
bool cmp(pair<int, int> x, pair<int, int> y){
return x.first + x.second < y.first + y.second;
}
void ins(int x){
int med;
if(down.size()) med = *down.rbegin();
else med = 1e9 + 7;
if(med < x){
up.insert(x);
sumr += 0ll + x;
} else{
down.insert(x);
suml += 0ll + x;
}
if(down.size() > up.size() + 1){
up.insert(*down.rbegin());
sumr += 0ll + *down.rbegin();
suml -= 0ll + *down.rbegin();
down.erase(down.find(*down.rbegin()));
return;
}
if(up.size() > down.size()){
down.insert(*up.begin());
suml += 0ll + *up.begin();
sumr -= 0ll + *up.begin();
up.erase(up.find(*up.begin()));
}
}
void in(){
cin >> k >> n;
val.push_back({0, 0});
for(int i = 1; i <= n; i++){
char p, q;
int s, t;
cin >> p >> s >> q >> t;
if(p == q) ans += 0ll + abs(s - t);
else val.push_back({s, t});
}
sort(val.begin(), val.end(), cmp);
len = val.size() - 1;
}
void sol(){
ans += 0ll + len;
for(int i = 1; i <= len; i++){
ins(val[i].first);
ins(val[i].second);
pre[i] = sumr - suml;
}
long long res = pre[len];
if(k == 2){
up.clear();
down.clear();
sumr = suml = 0;
for(int i = len; i >= 1; i--){
ins(val[i].first);
ins(val[i].second);
res = min(res, sumr - suml + pre[i - 1]);
}
}
cout << ans + res << '\n';
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
in();
sol();
return 0;
}
