include <bits/stdc++.h>

using namespace std; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); string s; cin >> s; int r=0; bool t=false; for (char c : s) { r+=c-'0'; if (c=='0') t=true; }

if (!t or r%3!=0) 
{
    cout << -1;
} else 
{
    sort(s.rbegin(), s.rend());
    cout<<s;
}
return 0;

}

include <bits/stdc++.h>

using namespace std; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); string s; cin >> s; int r=0; bool t=false; for (char c : s) { r+=c-'0'; if (c=='0') t=true; }

if (!t or r%3!=0) 
{
    cout << -1;
} else 
{
    sort(s.rbegin(), s.rend());
    cout<<s;
}
return 0;

}

include<bits/stdc++.h>

using namespace std; int main() { long long n; cin>>n; vector<long long> a(n); long long s=0,dem=0; for(int i=0;i<n;i++) { cin>>a[i]; if(a[i]>s) { s=a[i]; dem=1; } else if(a[i]==s) { dem++; } } cout<<dem<<endl; }

include<bits/stdc++.h>

using namespace std; int main() { long long n; cin>>n; vector<long long> a(n); long long s=0,dem=0; for(int i=0;i<n;i++) { cin>>a[i]; if(a[i]>s) { s=a[i]; dem=1; } else if(a[i]==s) { dem++; } } cout<<dem<<endl; }