#include <bits/stdc++.h>
using namespace std;
double dp[2005][2005];
int main() {
  int n, t;
  double p, ans = 0;
  scanf("%d%lf%d", &n, &p, &t);
  dp[0][0] = 1;
  for (int i = 0; i <= t; i++) {
    for (int j = 0; j <= n; j++) {
      dp[i + 1][j] += dp[i][j] * (1 - p);
      dp[i + 1][min(j + 1, n)] += dp[i][j] * p;
    }
  }
  for (int i = 0; i <= n; i++) ans += dp[t][i] * i;
  printf("%.6f\n", ans);
  return 0;
}
