#pragma region
#pragma GCC target("avx2")
#pragma GCC optimize("03")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std; typedef long double ld; typedef long long ll;
typedef unsigned long long ull;
#define endl "\n"
#define MP make_pair
#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define FORR(x,arr) for(auto& x:arr)
#define PII pair<int, int>
#define PLL pair<ll, ll>
#define VPII vector<PII>
#define VPLL vector<PLL>
#define FI first 
#define SE second
#define ALL(x) (x).begin(), (x).end()
constexpr int INF=1<<30; constexpr ll LINF=1LL<<60; constexpr ll mod=1e9+7; constexpr int NIL = -1;
template<class T>inline bool chmax(T &a, const T &b) { if (a<b) { a = b; return 1; } return 0; }
template<class T>inline bool chmin(T &a, const T &b) { if (b<a) { a = b; return 1; } return 0; }
#pragma endregion
//-------------------

int main(){
    cin.tie(0); ios::sync_with_stdio(false); //cout << fixed << setprecision(15);
    ll v,t,p; cin >> v >> t >> p;
    ll ans =  v*(p+1);
    ll cur = v*(p+1);
    ans++;

    ll cnt = 0;
    for(int i=32; i>=0; i--) {
        ll tmp = cnt + (1LL<<i);
        if(cur + tmp > t*tmp) cnt = tmp; 
    }
    // cout << cnt << endl;
    cout << ans+cnt << endl;
    return 0;
}