#include <bits/stdc++.h>
using namespace std;
const int maxn = 2000 + 200;
double a[maxn];
int n, t;
double p;
double dp[maxn][maxn];
int main() {
  scanf("%d %lf %d", &n, &p, &t);
  dp[0][0] = 1;
  for (int i = 1; i <= t; i++) {
    dp[i][0] = dp[i - 1][0] * (1 - p);
    for (int j = 1; j <= n; 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 = 0; i <= n; i++) ans += dp[t][i] * i;
  printf("%.12lf\n", ans);
  return 0;
}
