#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<61;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	ll V, T, P;
	cin >> V >> T >> P;
	ll l = 1, r = longINF;
	while (r - l > 1) {
		ll m = (l + r) >> 1;
		ll res = m - (m - 1) / T - 1 - P * V;
		if (res <= V && !((m - 1) % T == 0 && res == V)) l = m;
		else r = m;
	}
	cout << l << endl;
}