#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
#define pb push_back
#define ln '\n'
#define int long long
template <class _T>
bool chmin(_T &x, const _T &y){
bool flag = false;
if ( x > y ){
x = y; flag |= true;
}
return flag;
}
template <class _T>
bool chmax(_T &x, const _T &y){
bool flag = false;
if ( x < y ){
x = y; flag |= true;
}
return flag;
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int k, n; cin >> k >> n;
vector <pair<int,int>> p;
int res = 0;
for ( int i = 0; i < n; i++ ){
char a, b;
int x, y;
cin >> a >> x >> b >> y;
if ( x > y ) swap(x, y);
if ( a == b ){
res += y - x;
}
else{
p.pb({x, y});
}
}
res += (int)p.size();
sort(all(p), [&](pair <int,int> &x, pair <int,int> &y){
return x.first + x.second < y.first + y.second;
});
multiset <int> L, R;
int ls = 0, rs = 0;
const int inf = 1e16 + 1;
auto ins = [&](int x){
int Mx = L.empty() ? inf : *L.rbegin();
if ( x <= Mx ){
L.insert(x);
ls += x;
}
else{
R.insert(x);
rs += x;
}
while ( (int)L.size() > (int)R.size() ){
auto l = prev(L.end());
L.erase(l); ls -= *l;
R.insert(*l); rs += *l;
}
while ( (int)R.size() > (int)L.size() ){
auto r = R.begin();
R.erase(r); rs -= *r;
L.insert(*r); ls += *r;
}
return rs - ls;
};
n = (int)p.size();
vector <int> pref(n + 1);
for ( int i = 0; i < n; i++ ){
auto [l, r] = p[i];
ins(l);
pref[i + 1] = ins(r);
}
int ans = pref.back();
if ( k == 2 ){
L.clear(), R.clear();
ls = rs = 0;
for ( int i = n - 1; i >= 0; i-- ){
auto [l, r] = p[i];
ins(l);
chmin(ans, ins(r) + pref[i]);
}
}
cout << ans + res;
cout << '\n';
}
/*
1 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
*/
