#include <bits/stdc++.h>
using namespace std;
double dp[2005][2005], p;
int n, t;
int main() {
  scanf("%d%lf%d", &n, &p, &t);
  dp[0][0] = 1.0;
  for (int i = 1; i <= t; i++) {
    for (int j = 0; j <= n; j++) {
      if (j) dp[i][j] += dp[i - 1][j - 1] * p;
      if (j == n)
        dp[i][j] += dp[i - 1][j];
      else
        dp[i][j] += dp[i - 1][j] * (1 - p);
    }
  }
  double Ans = 0;
  for (int i = 1; i <= n; i++) Ans += dp[t][i] * i;
  printf("%lf\n", Ans);
}
