#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define fi first
#define se second
using namespace std;
using namespace __gnu_pbds;
using ll=long long;
using pii=pair<int, int>;
struct GetMedian{
multiset<ll> fi;
multiset<ll> se;
ll fsum, ssum;
void add(ll x){
se.insert(x);
ssum+=x;
while(fi.size() > se.size()){
ll val=*fi.rbegin();
fsum -= val;
auto it=fi.end();
--it;
fi.erase(it);
ssum+=val;
se.insert(val);
}
while(se.size() < fi.size()){
ll val=*se.begin();
ssum -= val;
se.erase(se.begin());
fsum+=val;
fi.insert(val);
}
}
ll get(){
ll med=*fi.rbegin();
return (med * fi.size() - fsum) + (ssum - med * se.size());
}
void clear(){
fi.clear();
se.clear();
fsum=ssum=0;
}
};
int k, n;
const int N=1e5+13;
int a[N];
ll res;
char c1, c2;
int x, y;
namespace sub1{
vector<int> v;
void solve(){
for(int i=1; i<=n; i++){
cin >> c1 >> x >> c2 >> y;
if(c1==c2){
res+=abs(x-y);
}
else{
v.push_back(x);
v.push_back(y);
++res;
}
}
sort(begin(v), end(v));
for(int c: v){
res+=abs(c-v[v.size()/2]);
}
cout << res;
}
}
vector<pair<int, int>> v;
ll l[N];
ll r[N];
void solve(){
cin >> k >> n;
if(k==1){
sub1::solve();
exit(0);
}
for(int i=1; i<=n; i++){
cin >> c1 >> x >> c2 >> y;
if(c1==c2){
res+=abs(x-y);
}
else{
if(x > y) swap(x, y);
v.push_back(make_pair(x, y));
++res;
}
}
if(v.empty()){
cout << res;
return;
}
sort(begin(v), end(v), [&](pii x, pii y){
return x.fi + x.se < y.fi + y.se;
});
GetMedian sus;
for(int i=1; i<=n; i++){
sus.add(v[i].fi);
sus.add(v[i].se);
l[i]=sus.get();
}
sus.clear();
for(int i=n; i>=1; i--){
sus.add(v[i].fi);
sus.add(v[i].se);
r[i]=sus.get();
}
ll ans=l[n];
for(int i=1; i<n; i++){
ans=min(ans, l[i]+r[i+1]);
}
cout << res+ans;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
solve();
}
