#include<bits/stdc++.h>//万能头文件
using namespace std;
struct P {
    char a;
    int cnt;
}p[30];
bool book[30];
bool cmp(struct P x, struct  P y)//sort中排序依据 
{
    return x.cnt < y.cnt;
}
int main() {
    char s[200];
    int k;
    scanf("%s\n%d", s, &k);
    for (int i = 0; i < 26; i++)
        p[i].a = 'a' + i;
    for (int i = 0; s[i] != '\0'; i++) {
        p[s[i] - 'a'].cnt++;
    }
    sort(p, p + 26, cmp);
    int strat, ans=0;//种类数
    for (int i = 0; i < 26; i++) {
        if (p[i].cnt) {
            strat = i;
            break;

        }
    }
    for (int i = strat; i < 26; i++) {
        if (k > p[i].cnt) {
            k -= p[i].cnt;
            
            book[p[i].a - 'a'] = 1;
        }
        else {
            ans = 26 - i;
            break;
        }
    }
    printf("%d\n", ans);
    if (ans) {
        for (int i = 0; i < strlen(s); i++) {
            if (book[s[i] - 'a'] == 1)continue;
            else printf("%c", s[i]);
        }
    }
    else printf("");
    return 0;
}