#include <bits/stdc++.h>
#include <bits/extc++.h>
#define int long long
#define fastio ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
using namespace std;
using namespace __gnu_pbds;
const int N = 2e5+5;
pair<int,int> bit[N];
int now[N];
pair<int,int> operator + (pair<int,int> a, pair<int,int> b){
return {a.first+b.first,a.second+b.second};
}
pair<int,int> operator - (pair<int,int> a, pair<int,int> b){
return {a.first-b.first,a.second-b.second};
}
void update(int pos, pair<int,int> val){
while(pos < N){
bit[pos] = bit[pos] + val;
pos += pos&-pos;
}
}
pair<int,int> query(int pos){
pair<int,int> res = {0,0};
while(pos){
res = res + bit[pos];
pos -= pos&-pos;
}
return res;
}
typedef tree<pair<int,int>,null_type,less<pair<int,int>>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
int t;
signed main(){
fastio
int k, n;
cin >> k >> n;
vector<int> tmp;
int ans = 1e18, anstmp = 0;
vector<pair<int,int>> v;
for(int i = 0;i < n;i++){
char a,b;
int x,y;
cin >> a >> x >> b >> y;
if(a == b) anstmp += abs(x-y);
else{
anstmp++;
tmp.push_back(x);
tmp.push_back(y);
v.push_back({x,y});
}
}
sort(tmp.begin(),tmp.end());
sort(v.begin(),v.end(),[&](auto a, auto b){
return a.first+a.second < b.first+b.second;
});
ordered_set s;
for(int i = 0;i < v.size();i++){
auto [x,y] = v[i];
s.insert({x,t++});
s.insert({y,t++});
update(lower_bound(tmp.begin(),tmp.end(),x)-tmp.begin()+1,{1,x});
update(lower_bound(tmp.begin(),tmp.end(),y)-tmp.begin()+1,{1,y});
int med = (*s.find_by_order(s.size()/2)).first;
pair<int,int> q1 = query(N-1)-query(lower_bound(tmp.begin(),tmp.end(),med)-tmp.begin()+1), q2 = query(lower_bound(tmp.begin(),tmp.end(),med)-tmp.begin());
now[i] = (q1.second-med*q1.first) + (med*q2.first-q2.second);
}
ans = min(ans,now[v.size()-1]);
s.clear();
fill(bit,bit+N,make_pair(0,0));
for(int i = v.size()-1;i >= 0;i--){
auto [x,y] = v[i];
s.insert({x,t++});
s.insert({y,t++});
update(lower_bound(tmp.begin(),tmp.end(),x)-tmp.begin()+1,{1,x});
update(lower_bound(tmp.begin(),tmp.end(),y)-tmp.begin()+1,{1,y});
int med = (*s.find_by_order(s.size()/2)).first;
pair<int,int> q1 = query(N-1)-query(lower_bound(tmp.begin(),tmp.end(),med)-tmp.begin()+1), q2 = query(lower_bound(tmp.begin(),tmp.end(),med)-tmp.begin());
if(i != 0) ans = min(ans,now[i-1]+(q1.second-med*q1.first) + (med*q2.first-q2.second));
else ans = min(ans,(q1.second-med*q1.first) + (med*q2.first-q2.second));
}
if(k==1){
cout << now[v.size()-1] + anstmp << "\n";
}else{
cout << ans+anstmp << "\n";
}
}
