#include<stdio.h>

unsigned long long factorial(int n)
{
    unsigned long long fact;
    fact=n;
    const unsigned int M = 1000000007;
    /*for (int counter = 1; counter <= n; counter++)
    {
         fact=(fact*counter)%M;  //now fact never can exceed 10^9+7  
    } */
    fact=fact%M;
  return fact;
}
int main()
{
    int a[3],i,c;
    unsigned long long f;
    for(i=0;i<3;i++)
        {
        scanf("%d",&a[i]);
    }
    c=(a[0]*0.5*a[2]+a[1]*0.5*a[2]);
    f=factorial(c);
    printf("%lld",f);
    return 0;
}