#include<bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast,O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,sse4,sse4.2,lzcnt,popcnt")
#define X first
#define Y second
#define SZ(x) ll(x.size())
#define pb push_back
#define Mp make_pair
#define all(x) x.begin(), x.end()
using ll = long long;
using pii = pair<int, int>;
const int INF = 1e9;
struct sum_set {
multiset<int> st;
ll sum=0;
void insert(int x) {
st.insert(x);
sum += x;
}
void erase(int x) {
st.erase(st.find(x));
sum -= x;
}
};
struct ds {
sum_set L, R;
void fix() {
while(SZ(R.st)>SZ(L.st)) {
int x = *R.st.begin();
L.insert(x);
R.erase(x);
}
while(SZ(R.st)+1<=SZ(L.st)-1) {
int x = *L.st.rbegin();
L.erase(x);
R.insert(x);
}
}
void insert(int x) {
if(SZ(L.st) && x<=*L.st.rbegin()) L.insert(x);
else R.insert(x);
fix();
}
void erase(int x) {
if(SZ(L.st) && x<=*L.st.rbegin()) L.erase(x);
else R.erase(x);
fix();
}
ll calc() {
if(L.st.empty()) return 0;
return SZ(L.st)*(*L.st.rbegin()) - L.sum + R.sum - SZ(R.st)*(*L.st.rbegin());
}
} L, R;
const int MXN = 1e5+5;
int S[MXN], T[MXN];
ll ans, pre;
char P[MXN], Q[MXN];
int k, n;
int32_t main() {
cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
cin >> k >> n;
vector<pii> vc;
for(int i=0; i<n; i++) {
cin >> P[i] >> S[i] >> Q[i] >> T[i];
if(P[i]==Q[i]) pre += abs(S[i]-T[i]);
else pre++, vc.pb(Mp(S[i], T[i]));
}
for(auto [s, t] : vc) R.insert(s), R.insert(t);
ans = pre+R.calc();
if(k==1) {
cout << ans << '\n';
return 0;
}
sort(all(vc), [&](pii x, pii y) {
return x.X+x.Y<y.X+y.Y;
});
for(auto [s, t] : vc) {
L.insert(s); L.insert(t);
R.erase(s); R.erase(t);
ans = min(ans, pre+L.calc()+R.calc());
}
cout << ans << '\n';
return 0;
}
