#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<char, int> pi;
#define all(x) (x).begin(), (x).end()
#define X first
#define Y second
int n;
vector<pi> qs;
ll f(int r, int s) {
ll ret = 0;
for(auto &x : qs) {
if(x.X == 'L') {
int ud = s - 1;
ret += max(0, x.Y - ud);
}else if(x.X == 'R') {
int ud = n - s;
ret += max(0, x.Y - ud);
}else{
int ud = n - r;
ret += max(0, x.Y - ud);
}
}
return ret;
}
void solve(){
int q;
cin >> n >> q;
qs.resize(q);
for(auto &x : qs) cin >> x.X >> x.Y;
ll najvise = max(f(n, 1), f(n, n));
ll najmanje = 0;
if(n % 2) {
int sred = (n + 1) / 2;
najmanje = min({f(1, sred - 1), f(1, sred), f(1, sred + 1)});
}else najmanje = min(f(1, n / 2), f(1, n / 2 + 1));
//cout << najvise << " " << najmanje << "\n";
cout << najvise - najmanje << "\n";
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
solve();
return 0;
}
