#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
using namespace std;
typedef long long ll;
typedef double dbl;
typedef pair<ll,ll> pii;
const int maxn = 1e5+5;
ll K,N,sum,cnt = 1e9+5,a,b,asum;
char c,d;
vector<pii> swp;
int main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
cin >> K >> N;
int temp = 0;
for(int i =1; i <= N;i++){
cin >> c >> a >> d >> b;
sum += abs(a-b);
if(c == d){
temp++;
continue;
}
asum += a;
if(a > b)swap(a,b);
swp.pb({a,0});
swp.pb({b,1});
}
sort(swp.begin(),swp.end());
ll l = 0, r = asum,posl = 0,posr = N-temp,i = 0,prv = 0;
pii cur;
while(i < swp.size()){
cur = swp[i];
r -= (cur.fi-prv)*posr;
l += (cur.fi-prv)*posl;
cnt = min(cnt,l+r);
//cout << "DIST: " << cur.fi << "-" << prv << endl << cnt << " " << l << " " << r << endl;
if(cur.se == 0)posr--;
else posl++;
while(i+1 < swp.size() && swp[i+1].fi == cur.fi){
if(swp[i+1].se == 0)posr--;
else posl++;
i++;
}
i++;
prv = cur.fi;
}
cout << sum + cnt*2 + N - temp<< endl;
}
