#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using oset =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define int long long
#define ld long double
#define ar array
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define all(x) x.begin(), x.end()
#define f first
#define s second
#define endl "\n"
const int MOD = 1e9+7;
const int inf = 1e18;
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};
// -------------------------------------------------- Main Code --------------------------------------------------
int a = 0, b = 0;
multiset<int> leftt, rightt;
void add(int x) {
if (leftt.empty() || x < *leftt.rbegin()) {
leftt.insert(x);
a += x;
if ((leftt.size()+rightt.size())%2 == 0 && leftt.size() > rightt.size()) {
a -= *leftt.rbegin();
b += *leftt.rbegin();
rightt.insert(*leftt.rbegin());
leftt.erase(leftt.find(*leftt.rbegin()));
}
}
else {
rightt.insert(x);
b += x;
if (rightt.size() > leftt.size()) {
a += *rightt.begin();
b -= *rightt.begin();
leftt.insert(*rightt.begin());
rightt.erase(rightt.begin());
}
}
}
void sol() {
int k, n; cin >> k >> n;
vector<array<int, 2>> arr;
int sameSide = 0;
for (int i = 0; i < n; i++) {
char a, b; int x, y;
cin >> a >> x >> b >> y;
if (a == b) sameSide += abs(x-y);
else arr.pb({x, y});
}
n = arr.size();
sameSide += n;
if (n == 0) { cout << sameSide << endl; return; }
sort(all(arr), [&](array<int, 2> a, array<int, 2> b) {return a[0]+a[1] < b[0]+b[1];});
vi pref(n);
for (int i = 0; i < n; i++) {
add(arr[i][0]); add(arr[i][1]);
int median = *leftt.rbegin();
pref[i] = median*leftt.size() - a + b - median*rightt.size();
}
if (k == 1) {cout << pref[n-1]+sameSide << endl;return;}
leftt.clear(); rightt.clear(); a = 0, b = 0;
vi suff(n);
for (int i = n-1; i >= 0; i--) {
add(arr[i][0]); add(arr[i][1]);
int median = *leftt.rbegin();
suff[i] = median*leftt.size() - a + b - median*rightt.size();
}
int ans = pref[n-1];
for (int i = 0; i < n-1; i++) ans = min(ans, pref[i]+suff[i+1]);
cout << sameSide+ans << endl;
}
signed main () {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
sol();
}
return 0;
}
