#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ii = pair<int, int>;
const int mod = 1e9 + 7;
const int inf = 1e9;
const int N = 2e3 + 10;
double dp[N][N];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, t;
  double p;
  cin >> n >> p >> t;
  dp[0][0] = 1.0;
  for (int i = 0; i < t; i++) {
    for (int j = 0; j <= n; j++) {
      if (j == n) {
        dp[i + 1][j] += dp[i][j];
      } else {
        dp[i + 1][j] += dp[i][j] * (1.0 - p);
        dp[i + 1][j + 1] += dp[i][j] * p;
      }
    }
  }
  double ans = 0;
  for (int i = 1; i <= n; i++) {
    ans += dp[t][i] * i;
  }
  cout << fixed << setprecision(6) << ans << '\n';
  return 0;
}
