#include<stdio.h>

int any(char s1[], char s2[]) {
    int i;
    int j;

    for (i = 0; s2[i] != '\0'; ++i)
        for (j = 0; s1[j] != '\0'; ++j)
            if (s2[i] == s1[j])
                return j;

    return -1;
}

int main() {
    char test_str[] = "blargh";
    char test_chars[] = "cab";
    int result = any(test_str, test_chars);
    printf("%d\n", result);
}