#include <bits/stdc++.h>
#define int long long
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
using namespace std;
signed main() {
ios_base::sync_with_stdio(false); cin.tie(nullptr);
int n,k; cin >> k >> n;
int sum=0;
vector<pair<int,pair<int,int>>> a;
for (int i = 0; i < n; i++){
char p,q; int s,t; cin >> p >> s >> q >> t;
if(s>t) swap(s,t);
if(p!=q) {
a.push_back({s+t,{s*2,t*2}});
sum++;
}
sum+=abs(s-t);
}
n=sz(a);
sort(all(a));
if(n==0){
cout << sum << "\n";
return 0;
}
if(k==1){
int med1=(a[n/2].first+a[(n-1)/2].first)/2;
int med2=(a[n/2].first+a[(n-1)/2].first+1)/2;
if(med1%2) med1++;
else if(med2%2) med2--;
int sm1=0;
int sm2=0;
for (int i = 0; i < n; i++)
{
sm1+=max(0LL,max(a[i].second.first-med1,med1-a[i].second.second));
sm2+=max(0LL,max(a[i].second.first-med2,med2-a[i].second.second));
}
sum+=max(sm1,sm2);
}
cout << sum << "\n";
return 0;
}
