#include <string.h>
char *strpbrk(const char *string1, const char *string2);
The strpbrk() function locates the first occurrence in the string pointed to by string1 of any character from the string pointed to by string2.
If successful, strpbrk() returns a pointer to the character.
If string1 and string2 have no characters in common, strpbrk() returns a NULL pointer.