#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template <class T>
using indexedset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long ll;
int main(){
int k, n;
cin >> k >> n;
vector<pair<ll, ll>> deals;
ll ans = 0;
for (int i = 0; i < n; i++){
char a, b;
ll c, d;
cin >> a >> c >> b >> d;
if (a == b) ans += max(d,c)-min(d,c);
else deals.push_back({min(c,d), max(c,d)});
}
ans += deals.size();
if (k == 1){
vector<ll> v;
for (auto x : deals) v.push_back(x.first), v.push_back(x.second);
sort(v.begin(), v.end());
ll med = v[v.size()/2];
for (ll x : v) ans += abs(x-med);
}else{
sort(deals.begin(), deals.end(), [&](auto x, auto y){
return (x.first+x.second)<(y.first+y.second);
});
multiset<ll> fh, fb, lh, lb;
ll last = 0;
ll first = 0;
ll best = 1e9;
for (int i = 0; i < (int) deals.size(); i++){
last += deals[i].first + deals[i].second;
lh.insert(deals[i].first);
lh.insert(deals[i].second);
}
while (lh.size() > lb.size()){
lb.insert(*lh.begin());
last -= 2 * (*lh.begin());
lh.erase(lh.begin());
}
best = last;
for (int i = 0; i < deals.size(); i++){
first += deals[i].second + deals[i].first;
fh.insert(deals[i].first);
fh.insert(deals[i].second);
while (fh.size() > fb.size()){
fb.insert(*fh.begin());
first -= 2 * (*fh.begin());
fh.erase(fh.begin());
}
if (lh.count(deals[i].first)) lh.erase(lh.find(deals[i].first)), last -= deals[i].first;
else lb.erase(lb.find(deals[i].first)), last += deals[i].first;
if (lh.count(deals[i].second)) lh.erase(lh.find(deals[i].second)), last -= deals[i].second;
else lb.erase(lb.find(deals[i].second)), last += deals[i].second;
while (lh.size() > lb.size()){
lb.insert(*lh.begin());
last -= 2 * (*lh.begin());
lh.erase(lh.begin());
}
while (lh.size() < lb.size()){
ll number = *--lb.end();
lh.insert(number);
last += 2 * number;
lh.erase(lh.find(number));
}
best = min(best, first+last);
}
ans += best;
}
cout << ans << endl;
}
