#include <bits/stdc++.h>
using namespace std;
double dp[3000][3000];
int main() {
  long long n, t, i, j;
  double p;
  cin >> n >> p >> t;
  dp[1][1] = p;
  dp[1][0] = 1 - p;
  for (i = 2; i <= t; i++) {
    for (j = 0; j <= min(n, i); j++) {
      if (j == n)
        dp[i][j] = dp[i - 1][j] + dp[i - 1][j - 1] * p;
      else
        dp[i][j] = dp[i - 1][j] * (1 - p) + dp[i - 1][j - 1] * p;
    }
  }
  double ans = 0;
  for (i = 1; i <= min(n, t); i++) ans += i * dp[t][i];
  cout << setprecision(18) << ans;
  return 0;
}
