#include <bits/stdc++.h>
using namespace std;
#define nyahalo ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define otsumiko exit(0);
#define mikodanye priority_queue<pair<long long, long long>, vector<pair<long long, long long> >, greater<pair<long long, long long> > >
#define mikochi priority_queue<long long, vector<long long>, greater<long long> >
long long k, n, s[100069], t[100069], ca, cb, ad = 0, ans = 0, sz, md, fp, sp, cs, mn;
char p[100069], q[100069];
vector<long long> vc;
int main() {
nyahalo
long long i, j, ii;
cin >> k >> n;
if (k == 1) {
for (i=1; i<=n; i++) {
cin >> p[i] >> s[i] >> q[i] >> t[i];
ca = p[i]-'A';
cb = q[i]-'A';
if (ca == cb) {
ad += abs(s[i]-t[i]);
} else {
vc.push_back(s[i]);
vc.push_back(t[i]);
}
}
sort(vc.begin(), vc.end());
sz = vc.size();
md = sz/2;
for (i=0; i<sz; i++) {
ans += abs(vc[i]-vc[md]);
}
ans += sz/2;
ans += ad;
cout << ans << "\n";
otsumiko
//uwu
}
if (n<=100) {
for (i=1; i<=n; i++) {
cin >> p[i] >> s[i] >> q[i] >> t[i];
ca = p[i]-'A';
cb = q[i]-'A';
if (ca == cb) {
ad += abs(s[i]-t[i]);
} else {
vc.push_back(s[i]);
vc.push_back(t[i]);
}
}
sort(vc.begin(), vc.end());
sz = vc.size();
ans = 1e17;
if (sz == 0) {
ans = 0;
}
for (i=0; i<sz; i++) {
for (j=i+1; j<sz; j++) {
fp = vc[i];
sp = vc[j];
cs = 0;
for (ii=1; ii<=n; ii++) {
if (p[ii] == q[ii]) {
continue;
}
mn = min(abs(fp-s[ii])+abs(fp-t[ii])+1, abs(sp-s[ii])+abs(sp-t[ii])+1);
cs += mn;
}
ans = min(ans, cs);
}
}
ans += ad;
cout << ans << "\n";
otsumiko
}
cout << "sek\n";
otsumiko
}
