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

#define int long long
#define rep(i, n) for(int i = 0; i < (int)(n); ++i)

int solve(void) {
    string N;
    cin >> N;
    const int L = N.size();
    
    string S1(L, '4');
    if(N < S1) {
    	string ans(L - 1, '5');
    	cout << ans << "\n";
    	return 0;
    }
    
    string S2(L, '5');
    if(S2 <= N) {
    	cout << S2 << "\n";
    	return 0;
    }
    
    rep(i, L) {
    	if(N[i] == '4' or N[i] == '5') continue;
    	
    	string ans = N;
    	for(int j = i; j < L; ++j) ans[j] = '5';
    	
    	if(N[i] < '4') {
    		for(int j = i - 1; j >= 0; --j) {
    			if(ans[j] == '4') ans[j] = '5';
    			else if(ans[j] == '5') {ans[j] = '4'; break;}
    		}
    	}
    	
    	cout << ans << "\n";
    	return 0;
    }
    
    cout << N << "\n";
    
    return 0;
}

signed main(void) {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    
    int Testcases = 1;
    //cin >> Testcases;
    while(Testcases--) solve();
    
    return 0;
}