#include <bits/stdc++.h>
using namespace std;
// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e18
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
#define sz size()
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
// input
template<class T> void IN(T& x) {cin >> x;}
template<class H, class... T> void IN(H& h, T&... t) {IN(h); IN(t...); }
// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }
//===================//
// Added libraries //
//===================//
//===================//
//end added libraries//
//===================//
void program();
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
program();
}
//===================//
// begin program //
//===================//
const int MX = 1e5+2;
ll k, n;
char p[MX], q[MX];
ll s[MX], t[MX];
ll ans;
map<ll,ll> mp;
priority_queue<ll > maxHeap;
priority_queue<ll,vll,greater<ll>> minHeap;
ll smLeft, smRight;
void clearHeap() {
while(!maxHeap.empty()) maxHeap.pop();
while(!minHeap.empty()) minHeap.pop();
smLeft = 0;
smRight = 0;
}
void addPoint(ll x) {
if(!maxHeap.empty() && x > maxHeap.top()) {
minHeap.push(x);
smRight += x;
} else {
maxHeap.push(x);
smLeft += x;
}
while(maxHeap.size() > minHeap.size()) {
ll x = maxHeap.top(); maxHeap.pop();
smLeft -= x;
smRight += x;
minHeap.push(x);
}
while(maxHeap.size() < minHeap.size()) {
ll x = minHeap.top(); minHeap.pop();
smRight -= x;
smLeft += x;
maxHeap.push(x);
}
}
ll getHeap() {
ll x = maxHeap.top();
return maxHeap.size()*x - smLeft + smRight - minHeap.size()*x;
}
void program() {
IN(k,n);
RE(i,n) IN(p[i],s[i],q[i],t[i]);
RE(i,n) if(s[i] > t[i]) swap(s[i], t[i]);
RE(i,n) s[i] *= 2, t[i] *= 2;
RE(_,k) {
clearHeap();
priority_queue<lll> midPoints;
RE(i,n) if(p[i] != q[i]) {
if(_) {
midPoints.push({-(t[i]+s[i])/2,i});
} else {
midPoints.push({ (t[i]+s[i])/2,i});
}
}
ll lst = -1;
while(!midPoints.empty()) {
lll p = midPoints.top(); midPoints.pop();
if(_) {
p.fi = -p.fi;
if(p.fi != lst && lst != -1)
mp[p.fi] += getHeap();
}
int i = p.se;
addPoint(s[i]);
addPoint(t[i]);
if(!_)
mp[p.fi] = (ans = getHeap());
lst = p.fi;
}
}
if(k == 2) {
ans = INF;
FOR(p,mp) ans = min(ans, p.se);
if(mp.empty()) ans = 0;
}
RE(i,n) if(p[i] == q[i]) ans += abs(s[i]-t[i]);
RE(i,n) if(p[i] != q[i]) ans += 2;
ans /= 2ll;
OUTL(ans);
}
