#include <iostream>
#include <vector>
#include <array>
#include <cstdlib>
#include <algorithm>
#include <map>
#define ll long long
using namespace std;
char C, D;
multimap <ll, ll> mp, mp2;
vector <ll> X;
vector <array<ll, 2> > V;
ll k, n, l, r, f, mn = 1e18, t, sl, sr, tl, tr;
int main() {
cin >> k >> n;
if (k == 1) {
for (int i=0; i<n; ++i) {
cin >> C >> l >> D >> r;
if (l > r) swap(l, r);
if (C == D) f += r-l;
else {
X.push_back(l);
X.push_back(r);
}
}
sort(X.begin(), X.end());
for (auto u : X) {
f += abs(X[X.size()/2]-u);
}
cout << f+X.size()/2 << '\n';
return 0;
}
for (int i=0; i<n; ++i) {
cin >> C >> l >> D >> r;
if (l > r) swap(l, r);
if (C == D) f += r-l;
else V.push_back({l, r});
}
sort(V.begin(), V.end(), [](auto a, auto b) {
return a[0]+a[1] < b[0]+b[1];
});
if (V.size() == 1) f += V[0][1]-V[0][0]+1;
if (V.size() <= 1) {
cout << f << '\n';
return 0;
}
for (int i=0; i<V.size(); ++i) {
mp2.insert({V[i][0], i});
mp2.insert({V[i][1], i});
t += V[i][0]+V[i][1];
}
auto md = mp.begin();
auto md2 = mp2.begin();
for (int i=0; i<V.size()-1; ++i) {
sl += md2->first;
md2 = next(md2);
}
sl += md2->first;
sr = t-sl;
for (int i=0; i<V.size()-1; ++i) {
mp.insert({V[i][0], i});
mp.insert({V[i][1], i});
if (i) {
if (V[i][1] < md->first) {
tl -= md->first;
tr += md->first;
md = prev(md);
tl += V[i][0]+V[i][1];
}
else if (V[i][0] >= md->first) {
md = next(md);
tl += md->first;
tr -= md->first;
tr += V[i][0]+V[i][1];
}
else tl += V[i][0], tr += V[i][1];
}
else {
md = mp.begin();
tl += V[i][0], tr += V[i][1];
}
if (V[i][0] == V[i][1] && V[i][0] == md2->first) {
auto z = prev(md2);
if (z->first != md2->first) {
sl -= md2->first;
sr += md2->first;
md2 = prev(md2);
sr -= V[i][0]+V[i][1];
}
else {
md2 = next(md2);
sl += md2->first;
sr -= md2->first;
sl -= V[i][0]+V[i][1];
}
}
else if (V[i][1] <= md2->first) {
md2 = next(md2);
sl += md2->first;
sr -= md2->first;
sl -= V[i][0]+V[i][1];
}
else if (md2->first <= V[i][0]) {
sl -= md2->first;
sr += md2->first;
md2 = prev(md2);
sr -= V[i][0]+V[i][1];
}
else sl -= V[i][0], sr -= V[i][1];
mp2.erase(mp2.lower_bound(V[i][0]));
mp2.erase(mp2.lower_bound(V[i][1]));
mn = min(mn, ((md->first+next(md)->first)/2)*((ll)mp.size()/2)-tl+tr-((md->first+next(md)->first)/2)*((ll)mp.size()/2)+
((md2->first+next(md2)->first)/2)*((ll)mp2.size()/2)-sl+sr-((md2->first+next(md2)->first)/2)*((ll)mp2.size()/2));
}
cout << mn+V.size()+f << '\n';
}
