#include <bits/stdc++.h>
using namespace std;
priority_queue<int> lpq;
priority_queue<int, vector<int>, greater<int>> rpq;
int64_t L, R;
void insert(int x) {
int median = (lpq.size() ? lpq.top() : 1000000001);
if (x <= median) {
lpq.push(x);
L += x;
} else {
rpq.push(x);
R += x;
}
if (rpq.size() + 1 < lpq.size()) {
int nxt = lpq.top();
lpq.pop();
rpq.push(nxt);
L -= nxt;
R += nxt;
} else if (lpq.size() < rpq.size()) {
int nxt = rpq.top();
rpq.pop();
lpq.push(nxt);
R -= nxt;
L += nxt;
}
}
int64_t pref[100001];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int k, n;
int64_t same_side = 0;
vector<array<int, 2>> v = {{0, 0}};
cin >> k >> n;
for(int i = 0; i < n; i++) {
char a, b;
int x, y;
cin >> a >> x >> b >> y;
if (a == b) same_side += abs(x - y);
else v.push_back({x, y});
}
sort(v.begin(), v.end(), [](array<int, 2>&a, array<int, 2>&b){
return (a[0] + a[1] < b[0] + b[1]);
});
n = v.size() - 1;
same_side += n;
L = R = 0;
for(int i = 1; i < n + 1; i++) {
insert(v[i][0]);
insert(v[i][1]);
pref[i] = R - L;
}
int64_t ans = pref[n];
if (k == 2) {
while (lpq.size()) lpq.pop();
while (rpq.size()) rpq.pop();
L = R = 0;
for(int i = n; i; i--) {
insert(v[i][0]);
insert(v[i][1]);
ans = min(ans, R - L + pref[i - 1]);
}
}
cout << same_side + ans;
return 0;
}
