#include<bits/stdc++.h>
#define pb push_back
#define sz(x) (int)(x.size())
#define all(x) x.begin(), x.end()
#define int long long
#define pii pair<int, int>
#define inf 1e9
#define mod 1000000007
#define F first
#define S second
#define mkp(x, y) make_pair(x, y)
#define wopen(x) freopen((x),"w",stdout)
#define ropen(x) freopen((x),"r",stdin)
#define de(x) cout << #x << " = " << x << ' '
#define IO ios_base::sync_with_stdio(0); cin.tie(0);
using namespace std;
const int mxN = 2e6 + 5;
int k, n, s[mxN], t[mxN];
char p[mxN], q[mxN];
signed main() {
IO;
cin >> k >> n;
vector<int> v;
int ans = 0;
for(int i = 0; i < n; i++) {
cin >> p[i] >> s[i] >> q[i] >> t[i];
if(p[i] != q[i]) v.pb(s[i]), v.pb(t[i]), ans++;
else ans += abs(s[i] - t[i]);
}
sort(all(v));
if(sz(v) == 0) {
cout << ans << '\n';
return 0;
}
int mid = v[(sz(v)) / 2];
for(int i = 0; i < sz(v); i++) ans += abs(v[i] - mid);
cout << ans << '\n';
}
