#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2000;
int n, t;
double p, dp[MAXN + 1][MAXN + 1], ans = 0;
int main() {
  cin >> n >> p >> t;
  dp[0][0] = 1;
  for (int i = 0; i < t; i++)
    for (int j = 0; j <= n; j++) {
      if (j < n) {
        dp[i + 1][j + 1] += dp[i][j] * p;
        dp[i + 1][j] += dp[i][j] * (1 - p);
      } else
        dp[i + 1][j] += dp[i][j];
    }
  for (int i = 1; i <= n; i++) ans += dp[t][i] * i;
  cout << fixed;
  cout << setprecision(9) << ans;
  return 0;
}
