#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define repr(i,n) for(int i = (int)(n); i >= 0; i--)
#define all(v) v.begin(),v.end()
typedef long long ll;

ll gcd(ll a, ll b){
    ll r,temp;
    if (a < b){
        temp = a;
        a = b;
        b = temp;
    }
    while ( (r = a % b) != 0){
        a = b;
        b = r;
    }
    return b;
}

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