FCTRL:Getting Wa

#include<stdio.h>
#include<math.h>
int main()
{
unsigned long int k,n,i,sum=0,t;
   float z;
   scanf("%ld",&t);
   while(t>0)
   {
     i=1;
     sum=0;
      scanf("%ld",&n);
     while(pow(5,i)<=n)
   {
       k=i;
       z=(n/pow(5,k));
       sum=(sum+z);
       i++;
   }
  printf("%ld", sum);
  t--;
}
return 0;
}

It Gives me error while it is working for all test cases plz help me