#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
using namespace std;
const int N = 1e5 + 5;
long long pre[N];
long long suf[N];
long long lsum, rsum;
pair <int, int> a[N];
int n,m,k;
priority_queue <int> lheap, rheap;
void add(int x) {
int med = (lheap.size() ? lheap.top() : 1e9 + 1);
if (x <= med) {
lheap.push(x);
lsum += x;
if (lheap.size() > rheap.size() + 1) {
x = lheap.top();
lsum -= x;
rsum += x;
lheap.pop();
rheap.push(-x);
}
} else {
rheap.push(-x);
rsum += x;
if (lheap.size() < rheap.size()) {
x = -rheap.top();
rsum -= x;
lsum += x;
rheap.pop();
lheap.push(x);
}
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> k >> n;
long long same_side = 0;
for (int i = 1; i <= n; i++) {
char cx, cy;
int x, y;
cin >> cx >> x >> cy >> y;
if (cx == cy)
same_side += abs(x - y);
else {
if (x > y)
swap(x, y);
a[++m] = mp(x, y);
}
}
sort(a + 1, a + m + 1, [](pair <int, int> a, pair <int, int> b) {
return (a.fi + a.se < b.fi + b.se);
});
for (int i = 1; i <= m; i++) {
add(a[i].fi);
add(a[i].se);
pre[i] = rsum - lsum;
}
lsum = rsum = 0;
while (lheap.size())
lheap.pop();
while (rheap.size())
rheap.pop();
for (int i = m; i >= 1; i--) {
add(a[i].fi);
add(a[i].se);
suf[i] = rsum - lsum;
}
long long res = 1e18;
for (int i = 0; i <= m; i++)
res = min(res, pre[i] + suf[i + 1]);
if (k == 1)
res = pre[m];
cout << res + same_side + m;
return 0;
}
