#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define sz(x) (int) x.size()
int main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int k, n;
cin >> k >> n;
ll ans = 0;
vector<array<int, 2>> a;
for (int i = 0; i < n; i++) {
char t1, t2;
int l, r;
cin >> t1 >> l >> t2 >> r;
if (t1 == t2) {
ans += abs(l - r);
continue;
}
if (l > r) swap(l, r);
a.push_back({l, r});
}
n = a.size();
if (k == 1) {
vector<ll> v;
for (int i = 0; i < n; i++) {
v.push_back(a[i][0]);
v.push_back(a[i][1]);
}
sort(v.begin(), v.end());
for (int i = 0; i < sz(v); i++) {
ans += abs(v[i] - v[sz(v) / 2]);
}
cout << ans + sz(a) << '\n';
return 0;
}
sort(a.begin(), a.end(), [&] (array<int, 2> x, array<int, 2> y) {return x[0] + x[1] < y[0] + y[1];});
auto process = [&] (vector<int> &order, ll arr[]) {
ll sumL = 0, sumR = 0;
priority_queue<int> pqL;
priority_queue<int, vector<int>, greater<>> pqR;
for (auto i : order) {
pqL.push(a[i][0]);
sumL += a[i][0];
pqL.push(a[i][1]);
sumL += a[i][1];
while (pqL.size() > pqR.size()) {
int x = pqL.top();
pqL.pop();
sumL -= x;
pqR.push(x);
sumR += x;
}
while (pqL.top() > pqR.top()) {
int x = pqL.top(), y = pqR.top();
pqL.pop();
sumL -= x;
pqR.pop();
sumR -= y;
pqL.push(y);
sumL += y;
pqR.push(x);
sumR += x;
}
assert(pqL.size() == pqR.size());
arr[i] = sumR - sz(pqR) * pqL.top();
arr[i] += sz(pqL) * pqL.top() - sumL;
}
};
ll prf[n + 1]{}, suf[n + 1]{};
vector<int> order(n);
for (int i = 0; i < n; i++) {
order[i] = n - 1 - i;
}
process(order, suf);
for (int i = 0; i < n; i++) {
order[i] = i;
}
process(order, prf);
ll mn = suf[0];
for (int i = 0; i < n; i++) {
mn = min(mn, prf[i] + suf[i + 1]);
}
ans += mn;
cout << ans + sz(a) << '\n';
return 0;
}
