#include "stdio.h"
#include <string.h>
#include <stdio.h>
#include <String.h>
#define max_sring_size   100
#define max_Pattern_size   100
int  Failure[max_Pattern_size];
void fail(char  *Pat )
{  
	int  i,j,n=strlen(Pat);
	Failure [ 0 ] = -1;
	for ( j = 1;  j < n;  j ++)  {
		i  =  Failure [ j -1 ];
		while ((Pat [ j ] != Pat [ i +1 ])&& ( i  >= 0))
			i = Failure [ i ];
		if ( Pat[j] == Pat [ i + 1] )
			Failure[j]= i + 1;
		else  
			Failure [j] =  -1;
	}
}  
int match ( char *String,  char *Pat)
{  
	int i = 0, j = 0;
	int  lens = strlen ( String );
	int  lenp = strlen ( Pat);
	while   ( i <  lens  &&  j <lenp ) {
		if  (String [i] ==  Pat[j] ){
			i ++;  
			j ++;
		}
		else  if  ( j== 0 )   
			i ++;                
		else  
			j=Failure [j-1] + 1;  
	}
	return  (( j ==  lenp )  ?  ( i - lenp )  :  -1 );
}
void main ()
{
	char s[]="Sit please.";
	char t[]="please ";
	int po=match(s,t);
	printf("%d",po);
}