#include <bits/stdc++.h>
using namespace std;
#define forn(i,n) for(int i=0;i<int(n);i++)
#define forsn(i,s,n) for(int i=int(s);i<int(n);i++)
#define dforn(i,n) for(int i=int(n)-1;i>=0;i--)
#define dforsn(i,s,n) for(int i=int(n)-1;i>=int(s);i--)
#define sz(c) int((c).size())
#define all(c) begin(c), end(c)
typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> ii;
#define fst first
#define snd second
const ll INF=1e18;
struct Median{
multiset<int> l,r;
ll lsum,rsum;
Median(){
l.clear(),r.clear();
lsum=0,rsum=0;
}
void balance(){
if(sz(l)>sz(r)+1){
rsum+=*l.rbegin(); lsum-=*l.rbegin();
r.insert(*l.rbegin());
l.erase(prev(end(l)));
}
if(sz(r)>sz(l)){
rsum-=*begin(r); lsum+=*begin(r);
l.insert(*begin(r));
r.erase(begin(r));
}
}
int getMedian(){
return *l.rbegin();
}
void add(int x){
if(l.empty()||x<getMedian()){
lsum+=x,l.insert(x);
}else{
rsum+=x,r.insert(x);
}
balance();
}
void erase(int x){
auto it=r.find(x);
if(it!=end(r)){
rsum-=x,r.erase(it);
}else{
lsum-=x,l.erase(l.find(x));
}
balance();
}
ll getCost(){
return rsum-lsum+(sz(r)-sz(l))*getMedian();
}
};
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
int k,n;
cin>>k>>n;
vector<ii> pos;
ll res=0;
forn(i,n){
char p,q;
int s,t;
cin>>p>>s>>q>>t;
if(p==q) res+=abs(s-t);
else pos.emplace_back(s,t);
}
int m=sz(pos);
res+=m;
sort(all(pos),[&](const ii &lhs, const ii &rhs){
return lhs.fst+lhs.snd<rhs.fst+rhs.snd;
});
vector<ll> pref(m+1,0);
Median ds;
forn(i,m){
ds.add(pos[i].fst),ds.add(pos[i].snd);
pref[i+1]=ds.getCost();
}
if(k==1){
res+=pref[m];
}else{
ds=Median();
vector<ll> suff(m+1,0);
dforn(i,m){
ds.add(pos[i].fst),ds.add(pos[i].snd);
suff[i]=ds.getCost();
}
ll mini=INF;
forn(i,m+1) mini=min(mini,pref[i]+suff[i]);
res+=mini;
}
cout<<res<<'\n';
return 0;
}
