#include <bits/stdc++.h>
using namespace std;
#define int long long
signed main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int k, n;
cin >> k >> n;
int m = n;
vector<tuple<int, int, int>> num;
vector<int> all;
int ans = 0;
for (int i = 0; i < n; i++) {
int a, b;
char c, d;
cin >> c >> a >> d >> b;
if (c == d) {
m--;
ans += abs(b-a);
} else {
ans++;
all.push_back(a);
all.push_back(b);
num.push_back({a+b, a, b});
}
}
//~ if (k == 1) {
sort(all.begin(), all.end());
int x = all[all.size()/2];
for (int i : all) {
ans += abs(i-x);
}
cout << ans << endl;
//~ } else {
//~ sort(num.begin(), num.end());
//~ }
}
