#include <iostream>
#include <bits/stdc++.h>

#define ll long long

using namespace std;

int countDigit(int n) {
      // Base case
    if (n == 0)
        return 1;

    int count = 0;

      // Iterate till n has digits remaining
    while (n != 0) {

          // Remove rightmost digit
        n = n / 10;

          // Increment digit count by 1
        ++count;
    }
    return count;
}

ll lnko(ll a, ll b){
    int m;
    do{
        m = a % b;
        a = b;
        b = m;
    }while(b != 0);
    return a;
}

long long lkkt(ll a, ll b){
    return a * b / lnko(a, b);
}

int main()
{
    long long a, b, n, lk;
    for(int i = 0 ; i < 3; i ++){
        cin >> a >> b >> n;
        lk = lkkt(a, b);
        if(countDigit(lk) == n){
            cout << lk << endl;
        }
        else if(countDigit(lk) > n)
            cout << -1 << endl;
        else{
            cout << lk;
            int j = countDigit(lk);
            while (j < n){
                cout << 0;
                j ++;
            }
        }
    }
    return 0;
}