#include<bits/stdc++.h>
using namespace std;
void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
cerr << h; if(sizeof...(t)) cerr << ", ";
DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL
#define FOR(i,a,b) for(int i = (a) ; i<(b) ; i++)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for(int i = (b)-1 ; i>=(a) ; i--)
#define R0F(i,a) ROF(i,0,a)
#define each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"
using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;
void setIO(string NAME = "") {
cin.tie(0)->sync_with_stdio(0);
if(sz(NAME)) {
freopen((NAME + ".inp").c_str(),"r",stdin);
freopen((NAME + ".out").c_str(),"w",stdout);
}
}
tcT> bool ckmin(T&a, const T&b) {
return b < a ? a = b, 1 : 0;
}
const int MOD = 1e9 + 7;
const int MX = 1e6+5;
int K, N;
ll pref[MX];
priority_queue<int> lo;
pqg<int> hi;
ll lsum = 0, rsum = 0;
void ins(int val) {
int curmed = sz(lo) ? lo.top() : MOD;
if(val <= curmed) {
lo.push(val);
lsum += val;
}
else {
hi.push(val);
rsum += val;
}
if(sz(hi)+1<sz(lo)) {
int tmp = lo.top();
lo.pop();
hi.push(tmp);
rsum += tmp;
lsum -= tmp;
}
else if(sz(hi) > sz(lo)) {
int tmp = hi.top();
hi.pop();
lo.push(tmp);
rsum -= tmp;
lsum += tmp;
}
}
void solve() {
cin>>K>>N;
V<pi> v;
v.pb({0,0});
ll same = 0;
FOR(i,1,N+1) {
char a,b;
int x,y;
cin>>a>>x>>b>>y;
if(a == b) { same += abs(x-y); }
else v.pb({x,y});
}
sort(all(v), [&](const pi&a, const pi&b){ return a.first + a.second < b.first + b.second; });
N = sz(v)-1;
same += N;
lsum = rsum = 0;
FOR(i,1,N+1) {
ins(v[i].first); ins(v[i].second);
pref[i] = rsum - lsum;
}
ll ans = pref[N];
if(K == 2) {
while(sz(hi)) hi.pop();
while(sz(lo)) lo.pop();
lsum = rsum = 0;
ROF(i,1,N+1) {
ins(v[i].first); ins(v[i].second);
ckmin(ans, rsum - lsum + pref[i-1]);
}
}
cout << ans + same << nl;
}
int main() {
setIO();
int t=1;
//cin>>t;
while(t-->0) {
solve();
}
return 0;
}
