#include <iostream>
#include <math.h>
using namespace std;
int main()
{
int n,i,a,b,suma;
cout << "numarul a=";
cin>>a;
cout << "numarul b=";
cin>>b;
cout << "numarul n=";
cin>>n;
suma=a+a*b;
for(i=1;i<=n;i++)
{
if(i+1<=n)
suma+=pow((a*b),(i+1));
}
cout<<"Rezultat="<<suma;
return 0;
}