#include <bits/stdc++.h>
using namespace std;
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
int k, n;
cin >> k >> n;
int64_t ans = 0;
vector<pair<int, int>> ranges;
vector<int> a;
for (int i = 0; i < n; i++) {
char p;
cin >> p;
int s;
cin >> s;
char q;
cin >> q;
int t;
cin >> t;
int l = min(s, t);
int r = max(s, t);
ans += r - l;
if (p != q) {
ans++;
a.push_back(l);
a.push_back(r);
ranges.emplace_back(l, r);
}
}
int64_t best = LLONG_MAX;
for (int x : a) {
int64_t res = ans;
for (auto [l, r] : ranges) {
if (r < x) {
res += int64_t(x - r) * 2;
} else if (l > x) {
res += int64_t(l - x) * 2;
}
}
best = min(best, res);
}
if (a.empty()) {
best = ans;
}
cout << best << '\n';
return 0;
}
