#include <stdio.h>

#define MAXLEN 1024

int locateSubstr ( char A[] , char B[] )
{
   int i, j, match;

   if (strlen(B) == 0) return 0;
   for (i=0; i<=(int)strlen(A)-(int)strlen(B); ++i) if (A[i] == B[0]) {
      match = 1;
      for (j=0; j<strlen(B); ++j) if (A[i+j] != B[j]) { match = 0; break; }
      if (match) return i;
   }
   return -1;
}

int foundPattern ( char A[] , char B[] , char C[] , int n )
{
   int i,j;

   i = 0;
   while (i < strlen(A)) {
      j = locateSubstr(&A[i],B);
      if (j < 0) return j;
      i += j;
      if (locateSubstr(&A[i+strlen(B)+n],C) == 0) return i;
      ++i;
   }
   return -1;
}

int main ()
{
   char A[MAXLEN], B[MAXLEN], C[MAXLEN];
   int i, n;

   printf("A = "); fgets(A,MAXLEN,stdin); A[strlen(A)-1] = '\0';
   printf("B = "); fgets(B,MAXLEN,stdin); B[strlen(B)-1] = '\0';
   printf("C = "); fgets(C,MAXLEN,stdin); C[strlen(C)-1] = '\0';
   printf("n = "); scanf("%d",&n);
   i = foundPattern(A,B,C,n);
   if (i >= 0)
      printf("The pattern B.{n}C is found in A at index %d\n", i);
   else
      printf("The pattern B.{n}C is not found in A\n");
}