#include <bits/stdc++.h>
using namespace std;
#define modulo 1000000007
#define mod(mod_x) ((((long long)mod_x+modulo))%modulo)
#define Inf 1000000000

int main(){
	
	long long V,T,P;
	cin>>V>>T>>P;
	
	long long ans = 1LL + V*(P+1) + (V*(P+1))/(T-1);
	
	cout<<ans<<endl;
	
		
	return 0;
}