#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2000;
const int MAXT = 2000;
long double dp[MAXT + 1][MAXN + 1];
int main() {
  int n;
  long double p;
  int t;
  cin >> n >> p >> t;
  dp[0][0] = 1;
  for (int i = 1; i <= t; ++i) {
    dp[i][0] = (1 - p) * dp[i - 1][0];
    dp[i][n] = dp[i - 1][n] + p * dp[i - 1][n - 1];
    for (int j = 1; j != n; ++j)
      dp[i][j] = (1 - p) * dp[i - 1][j] + p * dp[i - 1][j - 1];
  }
  long double ans = 0;
  for (int i = 0; i <= n; ++i) ans += i * dp[t][i];
  cout << setprecision(100) << ans << '\n';
  return 0;
}
