#include <stdio.h>
#include <string.h>
int mystr_idx(char *str, char *substr);
int main(int argc, char **argv)
{
	printf("Print you string\n");
	char s[100]; scanf("%s", s);
	printf("Print substring\n");
	char ss[100]; scanf("%s", ss);
	printf("Your substr has intex:%d\n", mystr_idx(s, ss));
	return 0;
}
int mystr_idx(char *str, char *substr)
{	
		int indx = strstr(str, substr) - str;
		if(strstr(str, substr) == NULL)
		{indx = -1;}
		
		return indx;
}