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