#include <bits/stdc++.h>
using namespace std;
int n, t;
double dp[2010][2010], p;
int main() {
  scanf("%d%lf%d", &n, &p, &t);
  dp[0][0] = 1;
  for (int i = 0; i < t; i++) {
    dp[i + 1][n] += dp[i][n];
    for (int j = 0; j < n; j++) {
      dp[i + 1][j] += dp[i][j] * (1 - p);
      dp[i + 1][j + 1] += dp[i][j] * p;
    }
  }
  double ans = 0;
  for (int i = 0; i <= n; i++) ans += dp[t][i] * i;
  printf("%.7f\n", ans);
  return 0;
}
