#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

int main() {
    string s;
    ll k;

    cin >> s >> k;

    ll n = s.size();
    ll l = 0;
    ll ans = 0;
    ll stt = 0;

    multiset<char> st;

    for(ll r = 0; r < n; r++) {
        st.insert(s[r]);

        while(*st.rbegin() - *st.begin() > k) {
            st.erase(st.find(s[l]));
            l++;
        }

        if(r - l + 1 > ans) {
            ans = r - l + 1;
            stt = l;
        }
    }

    cout << ans << '\n';
    cout << s.substr(stt, ans) << '\n';

    return 0;
}