#include <bits/stdc++.h>
using namespace std;
 
int main()
{
    string s;
    cin >> s;
    int val = 0, cnt = 0;
    string st = "";
    for (char x : s)
        if (x == '0') cnt++;
        else 
        {
            val += x-'0';
            st += x;
        }
    if (val%3 != 0 or cnt == 0)
    {
        cout << -1;
        return 0;
    } 
    sort(st.begin(),st.end(),greater<char>());
    for (char x : st) cout << x;
    for (int i = 1; i <= cnt; i++) cout << 0;
    return 0;
}

I2luY2x1ZGUgPGJpdHMvc3RkYysrLmg+CnVzaW5nIG5hbWVzcGFjZSBzdGQ7CgppbnQgbWFpbigpCnsKICAgIHN0cmluZyBzOwogICAgY2luID4+IHM7CiAgICBpbnQgdmFsID0gMCwgY250ID0gMDsKICAgIHN0cmluZyBzdCA9ICIiOwogICAgZm9yIChjaGFyIHggOiBzKQogICAgICAgIGlmICh4ID09ICcwJykgY250Kys7CiAgICAgICAgZWxzZSAKICAgICAgICB7CiAgICAgICAgICAgIHZhbCArPSB4LScwJzsKICAgICAgICAgICAgc3QgKz0geDsKICAgICAgICB9CiAgICBpZiAodmFsJTMgIT0gMCBvciBjbnQgPT0gMCkKICAgIHsKICAgICAgICBjb3V0IDw8IC0xOwogICAgICAgIHJldHVybiAwOwogICAgfSAKICAgIHNvcnQoc3QuYmVnaW4oKSxzdC5lbmQoKSxncmVhdGVyPGNoYXI+KCkpOwogICAgZm9yIChjaGFyIHggOiBzdCkgY291dCA8PCB4OwogICAgZm9yIChpbnQgaSA9IDE7IGkgPD0gY250OyBpKyspIGNvdXQgPDwgMDsKICAgIHJldHVybiAwOwp9