#include<deque>
#include<queue>
#include<vector>
#include<algorithm>
#include<iostream>
#include<set>
#include<cmath>
#include<tuple>
#include<string>
#include<chrono>
#include<functional>
#include<iterator>
#include<random>
#include<unordered_set>
#include<unordered_map>
#include<array>
#include<map>
#include<bitset>
#include<iomanip>
#include<list>
#include <numeric>
using namespace std;
typedef unsigned long long int ulint;
typedef long long int llint;
typedef long double lldo;
#define mp make_pair
#define mt make_tuple
#define pub push_back
#define puf push_front
#define pob pop_back
#define pof pop_front
#define fir first
#define sec second
#define res resize
#define ins insert
#define era erase
#define RE return 0
//ios::sync_with_stdio(false);
//std::cin.tie(0);
//<< setprecision(20)
const int mod=(int)1e9+7;
const llint big=(llint)(2.19e15+1);
const long double pai=3.141592653589793238462643383279502884197;
const long double ena=2.71828182845904523536;
const long double eps=1e-7;
template <class T,class U>bool mineq(T& a,U b){if(a>b){a=b;return true;}return false;}
template <class T,class U>bool maxeq(T& a,U b){if(a<b){a=b;return true;}return false;}
template <class T> void soun(T& ar)
{sort(ar.begin(),ar.end());ar.erase(unique(ar.begin(),ar.end()),ar.end());}
llint gcd(llint a,llint b){if(a%b==0){return b;}else{return gcd(b,a%b);}}
llint lcm(llint a,llint b){return a/gcd(a,b) *b;}
template<class T,class U> auto LB(T& ve,U in){return lower_bound(ve.begin(),ve.end(),in);}
template<class T,class U> auto UB(T& ve,U in){return upper_bound(ve.begin(),ve.end(),in);}
template<class T,class U> auto LBI(T& ve,U in){return LB(ve,in)-ve.begin();}
template<class T,class U> auto UBI(T& ve,U in){return UB(ve,in)-ve.begin();}
template<class T> void SO(T& ve){sort(ve.begin(),ve.end());}
template<class T> void REV(T& ve){reverse(ve.begin(),ve.end());}
int main(void){
int K,n,i;cin>>K>>n;
llint mto=0;
vector<tuple<llint,llint,llint>>ie;
ie.reserve(n);
for(i=0;i<n;i++){
char ca,cb;llint ba,bb;
cin>>ca>>ba>>cb>>bb;
if(ba>bb){swap(ba,bb);}
if(ca!=cb){mto++;ie.pub(mt(ba+bb,ba,bb));}
else{mto+=bb-ba;}
}
SO(ie);
n=ie.size();
if(n==0){cout<<mto<<endl;return 0;}
vector<llint>haL(n+1);
vector<llint>haR(n+1);
llint gen=0;
priority_queue<llint>que;//でかいのを出力に注意
for(i=0;i<n;i++){
que.push(-get<1>(ie[i]));gen+=get<1>(ie[i]);
que.push(-get<2>(ie[i]));gen+=get<2>(ie[i]);
gen+=2*que.top();que.pop();
haL[i+1]=gen;
}
while(que.size()>0){que.pop();}
gen=0;
for(i=1;i<=n;i++){
que.push(get<1>(ie[n-i]));gen-=get<1>(ie[n-i]);
que.push(get<2>(ie[n-i]));gen-=get<2>(ie[n-i]);
gen+=2*que.top();que.pop();
haR[i]=gen;
}
llint ans=big;
if(K==2){for(i=0;i<=n;i++){mineq(ans,haL[i]+haR[n-i]);}}
else{ans=haL[n];}
cout<<ans+mto<<endl;
return 0;
}
