#include <iostream>
#include <fstream>

using namespace std;

int main()
{
   ifstream f("be.in");
    for(int d=1;d<=3;d++){
      long long x, y, t;
      cin>>x>>y>>t;
      long long a=x, b=y, lkkt;
      long long m=a%b;
      while(m!=0){
         a=b;
         b=m;
         m=a%b;
      }
      lkkt=x/b*y;
      long long r=lkkt;
      long long j=0;
      while(r!=0){
         j++;
         r=r/10;
      }
      if(j<=t){
         cout<<lkkt;
         for(int i=j+1;i<=t;i++)cout<<0;
      cout<<endl;
      }else cout<<"-1"<<endl;
    }
    return 0;
}