#include "bits/stdc++.h"
using namespace std;
#ifdef Nero
#include "Deb.h"
#else
#define deb(...)
#endif
multiset<int> lo, hi;
long long sum1, sum2;
void fix() {
if (lo.size() > hi.size() + 1) {
int tmp = *lo.rbegin();
sum1 -= tmp;
lo.erase(lo.find(tmp));
sum2 += tmp;
hi.insert(tmp);
}
if (hi.size() > lo.size()) {
int tmp = *hi.begin();
sum2 -= tmp;
hi.erase(hi.find(tmp));
sum1 += tmp;
lo.insert(tmp);
}
}
void ins(int x) {
if (!lo.empty() && x >= *lo.rbegin()) {
sum2 += x;
hi.insert(x);
} else {
sum1 += x;
lo.insert(x);
}
fix();
}
long long get() {
int med = *lo.rbegin();
int sz1 = lo.size(), sz2 = hi.size();
long long ret = (long long) med * sz1 - sum1 + sum2 - (long long) med * sz2;
return ret;
}
void clear() {
lo.clear();
hi.clear();
sum1 = sum2 = 0;
}
int main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int k, n;
cin >> k >> n;
long long ans = 0;
vector<pair<int,int>> vec;
for (int i = 0; i < n; ++i) {
char z, z2;
int x, x2;
cin >> z >> x >> z2 >> x2;
//if (x > x2) swap(x, x2); important for proof only
if (z == z2) {
ans += abs(x - x2);
} else {
vec.emplace_back(x, x2);
}
}
if (!vec.size()) {
cout << ans << '\n';
return 0;
}
n = vec.size();
ans += n;
sort(vec.begin(), vec.end(), [](pair<int, int> i, pair<int, int> j) {
return i.first + i.second < j.first + j.second;
});
deb(vec); cout << '\n';
vector<long long> pref(n);
for (int i = 0; i < n; ++i) {
ins(vec[i].first);
ins(vec[i].second);
pref[i] = get();
}
clear();
vector<long long> suf(n);
for (int i = n - 1; i >= 0; --i) {
ins(vec[i].first);
ins(vec[i].second);
suf[i] = get();
}
long long res = ans + pref.back();
if (k == 2) {
for (int i = 0; i < n - 1; ++i) {
res = min(res, ans + pref[i] + suf[i + 1]);
}
}
cout << res << '\n';
return 0;
}
