#include <iostream>
#include <vector>
using namespace std;
vector <long long int> x;
vector <long long int> spid;
long long int n, m, a;
long long int d, h;
long long int dt, s;
int main(){
	ios_base::sync_with_stdio(0);
	cin>>n>>m;
	for(int i=0; i<n; i++){
		cin>>a;
		spid.push_back(a);
		x.push_back(d);
	}
	for(int k=0; k<m; k++){
		cin>>d>>h;
		for(int i=0; i<n; i++){
			x[i]=x[i]+spid[i]*(d-dt);
			if(x[i]>h){
				s=s+x[i]-h;
				x[i]=h;
			}
		}
		dt=d;
		cout<<s<<endl;
		s=0;
	}
	return 0;
}