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

#include<atcoder/all>
using namespace atcoder;
using mint=atcoder::modint1000000007;

#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#define int long long

#define rep(i,n) for(int i=0;i<(n);i++)
#define rng(i,l,r) for(int i=(l);i<(r);i++)
#define rrep(i,n) for(int i=(n)-1;i>=0;i--)
#define rrng(i,l,r) for(int i=(r)-1;i>=(l);i--)

#define fi first
#define se second
#define all(x) (x).begin(),(x).end()

struct fast_io{fast_io(){std::cin.tie(nullptr)->sync_with_stdio(false);}}_;

signed main(){
	string s;cin>>s;

	string now="";

	auto dfs=[&](auto dfs,int i,int flg,int sum)->void {
		// cout<<i<<" "<<flg<<" "<<sum<<" : "<<now<<endl;
		if(i==s.size()&&sum%3){
			reverse(all(now));
			while(now.back()=='0')now.pop_back();
			reverse(all(now));
			cout<<now<<endl;
			exit(0);
		}

		if(i==s.size())return;

		int r=10;
		if(!flg){
			r=(s[i]-'0'+1);
		}

		rrep(j,r){
			if(j==3)continue;
			now+='0'+j;
			dfs(dfs,i+1,flg||(j!=r-1),sum+j);
			now.pop_back();
		}
	};

	dfs(dfs,0,0,0);
}