paste bin

#include <cstdio>

int f(int target,int *a,int N)
{
    int i,j;

    if(N==1)
        return a[0]==target;
    int *b;
    bool pr,mr,tr=false;
    b=new int [N];
    for(i=0;i<N;i++)
    {
        for(j=0;j<i;j++)
            b[j]=a[j];
        for(j=i+1;j<N;j++)
            b[j-1]=a[j];
        pr=f(target-a[i],b,N-1);
        mr=f(target+a[i],b,N-1);
        if(target%a[i]==0)
            tr=f(target/a[i],b,N-1);
        if(pr||mr||tr)
            break;
    }
    
    delete [] b;
    return pr||mr||tr;
}

int main(void)
{
    int i,a[5];
    bool bf;
    while(1)
    {
        bf=true;
        for(i=0;i<5;i++)
        {
            scanf("%d",a+i);
            if(a[i]>0)
                bf=false;
        }
        if(bf)
            break;

        if(f(23,a,5)==true)
            printf("Possible\n");
        else
            printf("Impossible\n");
    }

    return 0;
}