int levenshtein(const char *s, int ls, const char *t, int lt)
{
        int a, b, c;

        
        if (!ls) return lt;
        if (!lt) return ls;

        
        if (s[ls - 1] == t[lt - 1])
                return levenshtein(s, ls - 1, t, lt - 1);

        
        a = levenshtein(s, ls - 1, t, lt - 1);
        b = levenshtein(s, ls,     t, lt - 1);
        c = levenshtein(s, ls - 1, t, lt    );

        if (a > b) a = b;
        if (a > c) a = c;

        return a + 1;
}

int main()
{
        const char *s1 = ;
        const char *s2 = ;
        printf(, s1, s2,
                levenshtein(s1, strlen(s1), s2, strlen(s2)));

        return 0;
}