80分TLE两个:( 求助

#include <bits/stdc++.h>
using namespace std;
struct chocolate
{
	unsigned long long int p;
	unsigned long long int c;
}choco[100001];
unsigned long long int N,B,ans;
bool cmp( chocolate a , chocolate b ){ return a.p < b.p ; }
int main()
{
	cin.tie( 0 );
	cin >> N >> B;
	for ( int i = 1 ; i <= N ; i ++ )
		cin >> choco[i].p >> choco[i].c;
	stable_sort( choco + 1 , choco + 1 + N , cmp );
	for ( int i = 1 ; i <= N ; i ++ )
	{

		for ( int j = 1 ; j <= choco[i].c ; j ++ )
		{
			if ( B >= choco[i].p )
			{
				B -= choco[i].p;
				ans ++;
			}
			else
			{
				cout << ans;
				return 0;
			}
		}
	}
	cout << ans;
	return 0;
}