// [+] dinhmanhhungwillwinioi2024
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 1e5 + 5;
int k, n;
ll ans = 0;
vector<pair<int, int>> arr;
ll pref[N], suf[N];
priority_queue<int> p1;
priority_queue<int, vector<int>, greater<int>> p2;
ll s1, s2;
void add(int x) {
if (!p1.empty() && x < p1.top()) {
p1.emplace(x);
s1 += x;
} else {
p2.emplace(x);
s2 += x;
}
while (p1.size() > p2.size()) {
int val = p1.top();
p1.pop();
s1 -= val;
p2.emplace(val);
s2 += val;
}
while (p2.size() > p1.size()) {
int val = p2.top();
p2.pop();
s2 -= val;
p1.emplace(val);
s1 += val;
}
}
inline ll cost() {
int med = p1.top();
return (1LL * med * p1.size() - s1) + (s2 - 1LL * med * p2.size());
}
void calc(ll dp[], bool rev) {
while (!p1.empty()) p1.pop();
while (!p2.empty()) p2.pop();
s1 = s2 = 0;
int m = arr.size();
for (int i = 1; i <= m; i++) {
add(arr[i - 1].first);
add(arr[i - 1].second);
dp[i] = cost();
}
if (rev) {
reverse(dp + 1, dp + m + 1);
}
}
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> k >> n;
for (int i = 1; i <= n; i++) {
char c1, c2;
int p1, p2;
cin >> c1 >> p1 >> c2 >> p2;
if (c1 == c2) {
ans += abs(p1 - p2);
} else {
arr.emplace_back(p1, p2);
}
}
sort(arr.begin(), arr.end(), [&] (const pair<int, int> &x, const pair<int, int> &y) {
return x.first + x.second < y.first + y.second;
});
calc(pref, false);
reverse(arr.begin(), arr.end());
calc(suf, true);
if (k == 1) {
ans += pref[arr.size()];
} else {
int m = arr.size();
ll res = ans + pref[m];
for (int i = 1; i < m; i++)
res = min(res, ans + pref[i] + suf[i + 1]);
ans = res;
}
cout << ans + arr.size();
return 0;
}
