i know the recursive relation .
F[l] := (k-1)(F[l-1] + F[l-2])
F[n] := (k-1)(F[n-1])
but my prog give WA here . i don know why . help me please.
here is my prog :

#include <stdio.h>
int n,k,z,lb,a[36],b[36];
void jam()
{
 int temp[36];
 int i;
 for (i=0;i<=lb;i++)
  temp[i] = b[i];
 for (i=0;i<=lb;i++)
  {
   b[i] = a[i] + b[i];
   if (b[i] > 9)
    {
     b[i] = b[i] - 10;
     b[i+1] = b[i+1] + 1;
    }
  }
  for (i=0;i<=lb;i++)
   a[i] = temp[i];
  if (b[lb+1]  > 0) lb++;
}

void zarb()
{
 int j;
 for (j = 0 ;j <= lb ; j ++)
 {
  b[j] = b[j] * (k-1);
  if (b[j] > 9)
   {
    b[j] = b[j]/10;
    b[j+1] = b[j+1] + b[j]%10;
   }
 }
  if (b[lb+1] > 0) lb++;
}

void main(void)
{
 scanf ("%d\n%d",&n,&k);
 a[0] = 0;
 b[0] = k;
 lb = 0;
 if (b[0] = 10)
  {
   b[0] = 0;
   b[1] = 1;
   lb = 1;
  }
 for (z=1;z<n-1;z++)
  {
   jam();
   zarb();
  }
 for (z=0;z<=lb;z++)
 {
  b[z] = b[z] * (k-1);
  if (b[z] > 9)
   {
    b[z+1] = b[z]/10;
    b[z] = b[z]%10;
   }
 }
 if (b[lb+1] > 0) lb++;
 for (z=lb;z>=0;z--)
  printf ("%d",b[z]);
}