#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define ALL(x) x.begin(),x.end()
using namespace __gnu_pbds;
using namespace std;
typedef long long ll;
typedef tree<pair<ll,pair<ll,ll>>,null_type,less<pair<ll,pair<ll,ll>>>,rb_tree_tag,tree_order_statistics_node_update> llset;
char t1,t2;
ll k,n,a,b;
ll lad,res,sumade,sumaiz;
bool cmp(pair<ll,ll> a,pair<ll,ll> b){return a.first+a.second<b.first+b.second;};
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin >> k >> n;
vector<pair<ll,ll>> nums;
vector<ll> dif;
for(ll i=0;i<n;i++){
cin >> t1 >> a >> t2 >> b;
if(t1==t2)lad+=abs(a-b);
else{
dif.push_back(a);
dif.push_back(b);
nums.push_back({min(a,b),max(a,b)});
}
}
n=nums.size();
sort(ALL(dif));
for(ll i=0;i<dif.size();i++){
res+=abs(dif[i]-dif[dif.size()/2]);
}
res+=n;
if(k==1){
cout << lad+res;
return 0;
}
sort(ALL(nums),cmp);
llset de;
vector<ll> sumaaaa(n);
for(ll i=0;i<n;i++){
if(de.empty()){
de.insert({nums[i].first,{i,0}});
}else{
ll valmedante=de.find_by_order(de.size()/2)->first;
sumade+=abs(valmedante-nums[i].first);
de.insert({nums[i].first,{i,0}});
if(nums[i].first<=valmedante){
ll valmednow=de.find_by_order(de.size()/2)->first;
sumade-=(valmedante-valmednow);
}
}
ll valmedante=de.find_by_order(de.size()/2)->first;
sumade+=abs(valmedante-nums[i].second);
de.insert({nums[i].second,{i,1}});
sumaaaa[i]=sumade;
}
for(ll i=0;i<n;i++){
//de 0 a i pref, de i+1 a n-1 suf
//quitar nums[i] del de
ll valmedante=de.find_by_order(de.size()/2)->first;
sumade-=abs(valmedante-nums[i].first);
de.erase(make_pair(nums[i].first,make_pair(i,0)));
if(nums[i].first>=valmedante){
ll valmednow=de.find_by_order(de.size()/2)->first;
sumade-=valmedante-valmednow;
}
valmedante=de.find_by_order(de.size()/2)->first;
sumade-=abs(valmedante-nums[i].second);
de.erase(make_pair(nums[i].second,make_pair(i,1)));
res=min(res,sumade+sumaaaa[i]+n);
}
cout << lad+res;
}
