#include <iostream>
#include <iomanip>
#include <string>
#include <math.h>
#include <algorithm>
#include <cstring>
#include <numeric>
#include <vector>
#include <bitset>
#include <map>
#include <set>
#include <queue>
#include <deque>
#include <stack>
#include <unordered_map>
#include <unordered_set>
using namespace std;
#define dbg(x) cerr<<#x<<": "<<x<<"\n";
/*
Shhhhh!
*/
priority_queue<long long>ll;
priority_queue<long long, vector<long long>, greater<long long>>rr;
long long l, r;
void add(long long x){
long long median=(ll.empty()?1e18:ll.top());
if(x<=median){
ll.push(x); l+=x;
}else{
rr.push(x); r+=x;
}
if((long long)rr.size()+1<(long long)ll.size()){
long long next=ll.top();
ll.pop();
rr.push(next);
l-=next;
r+=next;
}else if((long long)rr.size()>(long long)ll.size()){
long long next=rr.top();
rr.pop();
ll.push(next);
r-=next;
l+=next;
}
}
const long long maxN=1e5;
long long pref[maxN+1];
void solve(){
long long k, n, extra=0; cin>>k>>n;
using T=pair<long long, long long>;
vector<T>v;
for(long long i=0 ; i<n ; i++){
char p, q; long long s, t;
cin>>p>>s>>q>>t;
if(p==q) extra+=abs(s-t);
else v.push_back({s, t});
}
n=(long long)v.size();
sort(v.begin(), v.end(), [&](T a, T b){
return a.first+a.second<b.second+b.first;
});
for(long long i=0 ; i<n ; i++){
add(v[i].first);
add(v[i].second);
pref[i]=r-l;
}
long long ans=pref[n-1];
if(k==2){
while(!ll.empty()) ll.pop();
while(!rr.empty()) rr.pop();
l=r=0;
for(long long i=n-1 ; i>=0 ; i--){
add(v[i].first);
add(v[i].second);
ans=min(ans, r-l+pref[i-1]);
}
}
cout<<ans+extra+n<<"\n";
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
solve();
return 0;
}
