#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e5 + 7;
const int INF = 1e9 + 7;
struct Person{
int a, b;
bool operator < (const Person &oth){
return a + b < oth.a + oth.b;
}
};
struct TwoPQ{
ll sumLeft, sumRight;
priority_queue<int> Left;
priority_queue<int, vector<int>, greater<int>> Right;
void init(){
sumLeft = sumRight = 0;
while (!Left.empty())
Left.pop();
while (!Right.empty())
Right.pop();
Left.push(-INF);
Right.push(INF);
}
void insert(int a, int b){
Left.push(a), sumLeft += a;
Right.push(b), sumRight += b;
while (Left.top() > Right.top()){
int l = Left.top();
int r = Right.top();
Left.pop(), sumLeft -= l;
Right.pop(), sumRight -= r;
Left.push(r), sumLeft += r;
Right.push(l), sumRight += l;
}
}
ll solve(){
return sumRight - sumLeft;
}
} twoPq;
int k, n;
Person a[N];
ll l[N], r[N];
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> k >> n;
ll sum = 0;
for(int i = 1; i <= n; i++){
char x, y;
cin >> x >> a[i].a >> y >> a[i].b;
if (x == y){
sum += abs(a[i].a - a[i].b);
i--;
n--;
} else {
sum++;
}
}
sort(a + 1, a + 1 + n);
twoPq.init();
for(int i = 1; i <= n; i++){
twoPq.insert(a[i].a, a[i].b);
l[i] = twoPq.solve();
}
twoPq.init();
for(int i = n; i >= 1; i--){
twoPq.insert(a[i].a, a[i].b);
r[i] = twoPq.solve();
}
if (k == 1){
cout << sum + l[n];
} else {
ll res = 1e18;
for(int i = 0; i <= n; i++)
res = min(res, l[i] + r[i + 1]);
cout << res + sum;
}
return 0;
}
