#include <bits/stdc++.h>
typedef long long ll;
#define FOR(i, x, y) for(ll i=x; i<y; i++)
#define FORNEG(i, x, y) for(ll i=x; i>y; i--)
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<ll, null_type,less_equal<ll>, rb_tree_tag,tree_order_statistics_node_update>
ll addlater;
vector<vector<ll> > tings;
ordered_set sustree;
ll rsum, lsum;
ll median, nextmed;
bool cmp(vector<ll> a, vector<ll> b) { return a[0] + a[1] < b[0] + b[1]; };
void insert(ll a, ll b){
if (a>b) swap(a,b);
if (sustree.size() !=0) median = *sustree.find_by_order(sustree.size()/2 - 1), nextmed = *sustree.find_by_order(sustree.size()/2);
else median = a, nextmed = b;
if (a<=median && b>median) lsum += a, rsum += b;
else if (a<=median && b<=median) lsum += a+b-median, rsum += median;
else {
sustree.insert(a); sustree.insert(b);
median = *sustree.find_by_order(sustree.size()/2 - 1);
lsum += median, rsum += a+b-median;
goto skip;
}
sustree.insert(a); sustree.insert(b);
skip:;
}
int main(){
ll k, n;
cin.tie(0)->sync_with_stdio(0);
cin >> k >> n;
FOR(i,0,n){
char a,b;
ll x,y;
cin >> a >> x >> b >> y;
if (a==b) addlater += abs(x-y);
else tings.push_back({x,y});
}
n = tings.size();
addlater += n;
ll prefs[100001];
sort(tings.begin(), tings.end(), cmp);
rsum = 0; lsum = 0;
FOR(i,0,n){
insert(tings[i][0], tings[i][1]);
prefs[i] = rsum - lsum;
}
ll ans = prefs[n-1];
if (k==2){
sustree.clear();
rsum = 0; lsum = 0;
FORNEG(i, n-1, 0){
insert(tings[i][0], tings[i][1]);
ans = min(ans, rsum - lsum + prefs[i-1]);
}
}
cout << ans + addlater;
}
