#include <bits/stdc++.h>
double f[2010];
int main() {
  int n, t;
  double p;
  scanf("%d%lf%d", &n, &p, &t);
  f[0] = 1.0;
  for (int i = 0; i < t; i++) {
    for (int j = n; j >= 0; j--)
      if (j == n)
        f[j] = f[j - 1] * p + f[j];
      else if (j == 0)
        f[j] = f[j] * (1 - p);
      else
        f[j] = f[j - 1] * p + f[j] * (1 - p);
  }
  double ans = 0;
  for (int i = 0; i <= n; i++) ans += i * f[i];
  printf("%.8lf\n", ans);
  return 0;
}
