Untitled

#include <bits/stdc++.h>

using namespace std;
int main() {
	int n;
	int mid;
	int e=0;
	int sl;
	int a[100],b[100];
	cin>>n>>sl;
	mid=(n+1)/2;
	for (int i=1;i<=sl;i++) {
		cin>>a[i]>>b[i];
	}
	for (int i=1;i<=sl;i++) {
		if (abs(a[i]-mid)>abs(b[i]-mid)) {
			e+=abs(a[i]-mid)*10+abs(b[i]-mid)*5;
		} else if (abs(a[i]-mid)<abs(b[i]-mid)) {
			e+=abs(a[i]-mid)*5+abs(b[i]-mid)*10;
		} else if (abs(a[i]-mid)==abs(b[i]-mid)) {
			e+=abs(a[i]-mid)*15;
		}
	}
	cout<< e;
}