#include <bits/stdc++.h>
using namespace std;
#define ll long long
bool cmp(pair<ll, ll> a, pair<ll, ll> b)
{
return a.first + a.second < b.first + b.second;
}
priority_queue<ll> lpq;
priority_queue<ll, vector<ll>, greater<ll>> rpq;
ll lsum, rsum;
void insert(ll x) {
ll median = (lpq.size() ? lpq.top() : 1000000001);
if (x <= median)
{
lpq.push(x);
lsum += x;
}
else
{
rpq.push(x);
rsum += x;
}
if (rpq.size() + 1 < lpq.size())
{
ll nxt = lpq.top();
lpq.pop();
rpq.push(nxt);
lsum -= nxt;
rsum += nxt;
}
else if (lpq.size() < rpq.size())
{
ll nxt = rpq.top();
rpq.pop();
lpq.push(nxt);
rsum -= nxt;
lsum += nxt;
}
}
ll pref[100001];
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
ll k, n;
ll same_side = 0;
vector<pair<ll, ll>> v = {{0, 0}};
cin >> k >> n;
for (int i = 0; i < n; i++)
{
char a, b;
ll 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(), cmp);
n = v.size() - 1;
same_side += n;
lsum = rsum = 0;
for (int i = 1; i <= n; i++)
{
insert(v[i].first);
insert(v[i].second);
pref[i] = rsum - lsum;
}
ll ans = pref[n];
if (k == 2)
{
while (lpq.size())
lpq.pop();
while (rpq.size())
rpq.pop();
lsum = rsum = 0;
for (int i = n; i >= 1; i--)
{
insert(v[i].first);
insert(v[i].second);
ans = min(ans, rsum - lsum + pref[i - 1]);
}
}
cout << same_side + ans << "\n";
}
