#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
using namespace std;
const int N = 1e5 + 2;
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
int k, n; cin >> k >> n;
ll ans = 0;
vector<array<ll, 2>> a;
for (int i = 0; i < n; i++) {
char pp, qq;
ll x, y;
cin >> pp >> x >> qq >> y;
if (x > y) swap(x, y);
if (pp == qq) ans += y - x;
else a.push_back({x, y}), ans++;
}
sort(a.begin(), a.end(), [&] (array<ll, 2> i, array<ll, 2> j) {
return i[0] + i[1] < j[0] + j[1];
});
n = a.size();
if (n == 0) {
cout << ans << en;
return 0;
}
ll d = 0;
priority_queue<ll> p, q;
vector<ll> pref(n), suff(n);
for (int i = 0; i < n; i++) {
p.push(a[i][0]); d -= a[i][0];
q.push(-a[i][1]); d += a[i][1];
if (p.top() > -q.top()) {
d += 2 * (p.top() + q.top());
ll xx = p.top(); ll yy = q.top();
p.pop(); q.pop();
p.push(-yy); q.push(-xx);
}
pref[i] = d;
}
d = 0;
while (!p.empty()) p.pop();
while (!q.empty()) q.pop();
for (int i = n - 1; i >= 0; i--) {
p.push(a[i][0]); d -= a[i][0];
q.push(-a[i][1]); d += a[i][1];
if (p.top() > -q.top()) {
d += 2 * (p.top() + q.top());
ll xx = p.top(); ll yy = q.top();
p.pop(); q.pop();
p.push(-yy); q.push(-xx);
}
suff[i] = d;
}
if (k == 1) {
cout << ans + suff[0] << en;
return 0;
}
ll ad = suff[0];
for (int i = 0; i < n - 1; i++) smin(ad, pref[i] + suff[i + 1]);
cout << ans + ad << en;
return 0;
}
