#include <iostream>
#include <cstdio>
#include <vector>
#include <cmath>
#include <algorithm>
#include <set>
using namespace std;
using LL = long long;
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
int k, n;
cin >> k >> n;
LL fans = 0;
vector<pair<LL, pair<LL, LL>>> inv(0);
vector<LL> invnums(0);
while (n--)
{
char a, c;
LL b, d;
cin >> a >> b >> c >> d;
if (a == c)
{
if (b > d) fans += b - d;
else fans += d - b;
}
else
{
fans++;
invnums.push_back(b), invnums.push_back(d);
inv.push_back({ b + d, {b, d} });
}
}
n = inv.size();
sort(invnums.begin(), invnums.end()), sort(inv.begin(), inv.end());
LL llsum = 0, lrsum = 0, rlsum = 0, rrsum = 0, lmid = -1, rmid = -1;
multiset<LL> ll, lr, rl, rr;
for (int i = 0; i < n; i++)
{
rl.insert(-invnums[i]);
rlsum += invnums[i];
}
for (int i = n; i < 2 * n; i++)
{
rr.insert(invnums[i]);
rrsum += invnums[i];
}
rmid = -*rl.begin();
LL ans = rrsum - rlsum;
if (k == 2) for (int i = 0; i < n - 1; i++)
{
if (inv[i].second.first > rmid)
{
rrsum -= inv[i].second.first;
rr.erase(rr.find(inv[i].second.first));
if (inv[i].second.second <= rmid)
{
rlsum -= inv[i].second.second;
rl.erase(rl.find(-inv[i].second.second));
rmid = -*rl.begin();
}
else
{
rrsum -= inv[i].second.second;
rr.erase(rr.find(inv[i].second.second));
rrsum += rmid;
rr.insert(rmid);
rlsum -= rmid;
rl.erase(rl.begin());
rmid = -*rl.begin();
}
}
else
{
rlsum -= inv[i].second.first;
rl.erase(rl.find(-inv[i].second.first));
rmid = -*rl.begin();
if (inv[i].second.second > rmid)
{
rrsum -= inv[i].second.second;
rr.erase(rr.find(inv[i].second.second));
}
else
{
rlsum -= inv[i].second.second;
rl.erase(rl.find(-inv[i].second.second));
rmid = *rr.begin();
rlsum += rmid;
rl.insert(-rmid);
rrsum -= rmid;
rr.erase(rr.begin());
}
}
if (inv[i].second.first > lmid)
{
lr.insert(inv[i].second.first);
lrsum += inv[i].second.first;
if (inv[i].second.second <= lmid)
{
ll.insert(-inv[i].second.second);
llsum += inv[i].second.second;
lmid = -*ll.begin();
}
else
{
lr.insert(inv[i].second.second);
lrsum += inv[i].second.second;
lmid = *lr.begin();
lrsum -= lmid;
lr.erase(lr.begin());
ll.insert(-lmid);
llsum += lmid;
}
}
else
{
ll.insert(-inv[i].second.first);
llsum += inv[i].second.first;
if (inv[i].second.second >= lmid)
{
lrsum += inv[i].second.second;
lr.insert(inv[i].second.second);
}
else
{
llsum += inv[i].second.second;
ll.insert(-inv[i].second.second);
lrsum += lmid;
lr.insert(lmid);
llsum -= lmid;
ll.erase(ll.begin());
lmid = -*ll.begin();
}
}
ans = fmin(ans, (rrsum - rlsum) + (lrsum - llsum));
}
fans += ans;
cout << fans;
}
