300

//300
#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;

int main(void) {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);

    char a[11];
    int b;
    scanf("%s%d", a, &b);
    int len = strlen(a);
    sort(a, a + len);
    reverse(a, a + len);
    for (; atoi(a) > b; prev_permutation(a, a + len));
    printf("%s\n", a);
    return 0;
}