Hangdian 2124

no ac wr don't know why

code show as below:

#include<iostream>
using namespace std;
#include<algorithm>
int cmp(int a,int b)
{
    return a>b;
}
int main()
{
    long long l,n,a[605];
    while(cin>>l>>n&&l&&n)
    {
        int sum=0;
        for(int i=0;i<n;i++)
            cin>>a[i];
        sort(a,a+n,cmp);
        for(int i=0;i<n;i++)
            if(l>0)
        {
            sum++;
            l=l-a[i];
        }
        if(l>0)
        cout<<"impossible"<<endl;
        else
        cout<<sum<<endl;

    }
}