#include<bits/stdc++.h>
using namespace std;
#define int long long
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; i--)
#define fi first
#define se second
#define pb push_back
#define ALL(a) (a).begin(), (a).end()
#define task "kbsiudthw"
#define sz(a) (int)(a).size()
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef pair<int, ii> pii;
const int N = 1e5 + 5;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 2277;
int k, n;
multiset<int> L, R;
int sL, sR;
void Insert(int x){
if (L.empty() || *L.rbegin() >= x) L.insert(x), sL += x;
else R.insert(x), sR += x;
if (sz(L) - sz(R) > 1){
R.insert(*L.rbegin());
sR += *L.rbegin();
sL -= *L.rbegin();
L.erase(--L.end());
}
while (sz(R) - sz(L) > 0){
L.insert(*R.begin());
sL += *R.begin();
sR -= *R.begin();
R.erase(R.begin());
}
}
int getMedian(){
return *L.rbegin();
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
if (fopen(task".inp", "r")){
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
cin >> k >> n;
vector<ii> a;
int ans = 0;
FOR (i, 1, n){
char p, q;
int s, t; cin >> p >> s >> q >>t;
if (q == p) ans += abs(s - t);
else a.pb({s, t});
}
sort(ALL(a), [&](ii &A, ii &B){
return A.fi + A.se < B.fi + B.se;
});
n = sz(a);
vi pref(n+2, 0);
FOR (i, 1, n){
Insert(a[i-1].fi);
Insert(a[i-1].se);
int m = getMedian();
pref[i] = sz(L)*m - sL + sR - sz(R)*m;
}
ans += n;
if (k == 1) return cout << ans + pref[n], 0;
sL = sR = 0;
L.clear(); R.clear();
int ans2 = pref[n];
FORD(i, n, 1){
Insert(a[i-1].fi);
Insert(a[i-1].se);
int m = getMedian();
ans2 = min(ans2, sz(L) * m - sL + sR - sz(R) * m + pref[i-1]);
}
cout << ans + ans2 << '\n';
return 0;
}
