#include <bits/stdc++.h>

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;

using u128 = unsigned __int128;
using i128 = __int128;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    std::string s;
    std::cin >> s;
    int N = s.size();

    if (s[0] < '4') {
        std::cout << std::string(N - 1, '5');
    } else if (s[0] > '5') {
        std::cout << std::string(N, '5');
    } else {
        std::string t = s;
        for (int i = 0; i < N; i++) {
            if (s[i] == '5' || s[i] == '4') t[i] = s[i];
            else if (s[i] > '5') t[i] = '5';
            else if (s[i] < '4') {
                int j = i - 1;
                while (j >= 0 && t[j] != '5') j--;
                // 前面没有5，这变成N-1位的全5
                // 前面最近的5变4后后面全变5再直接退出
                if (j == -1) {
                    t = std::string(N - 1, '5');
                    break;
                } else {
                    t[j] = '4';
                    for (int k = j + 1; k < N; k++) {
                        t[k] = '5';
                    }
                    break;
                }
            }
        }
        std::cout << t << '\n';
    }

    return 0;
}