#include <stdio.h>
#include<math.h>
int main()
{
    double n,m;
    short int y;
    int i;
    char flag='N';
    scanf("%lf%lf%d",&n,&m,&y);
    for (i=1;i<m-1;i++)
    {
        if( (((int)(pow((double)i,n) )) % (int)m) == y)
        {
             printf("%d ",i);
            flag='Y';
        }
    }

    if(flag=='N')
        printf("-1");
    return(0);
}

pow(i,n) is a very big number (about 999^999)
So pow(i, n) don't fit into int type.

Try to write yourself Pow() function which
will calculate not i^n but (i^n)%m
And do it in integer numbers!
You don't need double in this problem.

Thank you.... now its working..