#include <bits/stdc++.h>
using namespace std;
int n, t;
double P;
double Dp[2020][2020];
bool Visited[2020][2020];
double Rec(int Pos, int T) {
  if (Pos == n) return 0.0;
  if (T == t) return 0.0;
  if (Visited[Pos][T]) return Dp[Pos][T];
  Visited[Pos][T] = true;
  double Move = 0.0, Stop = 0.0;
  Move = P * (1 + Rec(Pos + 1, T + 1));
  Stop = (1 - P) * Rec(Pos, T + 1);
  return Dp[Pos][T] = Move + Stop;
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> P >> t;
  cout << setprecision(6) << fixed;
  cout << Rec(0, 0);
}
