#include <bits/stdc++.h>
#define ST first
#define ND second
#define PB push_back
using namespace std;
using ll = long long;
using pi = pair<int,int>;
using vi = vector<int>;
const int nax = 100 * 1000 + 10;
const ll INF = 1e18;
int n, m, k;
int opn[nax], clo[nax];
vi all;
ll add = 0;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> k >> n;
for(int i = 0; i < n; ++i) {
char t1, t2;
int d1, d2;
cin >> t1 >> d1 >> t2 >> d2;
add += abs(d1 - d2);
if(t1 != t2) {
opn[m] = min(d1, d2);
clo[m] = max(d1, d2);
all.PB(d1);
all.PB(d2);
m++;
}
}
sort(all.begin(), all.end());
sort(opn, opn + m);
sort(clo, clo + m);
if(k == 1) {
int ptr = 0, ptr2 = 0;
ll Lsum = 0, Rsum = 0;
ll ans = INF;
for(int i = 0; i < m; ++i) Rsum += opn[i];
for(int x : all) {
while(ptr2 < m && clo[ptr2] < x) {
Lsum += clo[ptr2];
ptr2++;
}
while(ptr < m && opn[ptr] < x) {
Rsum -= opn[ptr];
ptr++;
}
ll d = (ll)x * ptr2 - Lsum - (ll)x * (m - ptr) + Rsum;
ans = min(ans, d);
}
cout << ans * 2 + add + m << "\n";
}
}
