#include <stdio.h>

    int f1 (int (*t)(int)) {
        int n=8;
        while ((*t)(n)) n--;
        return n;
    }
    int f2 (int n) {
        return n*n-6*n+5;
    }
 int main()
{
    printf("f1(f2) = %d\n",f1(f2));
return 0;
}