#include <bits/stdc++.h>
using namespace std;
double p;
double ans[2001][2001];
int main() {
  int i, j, n, t;
  scanf("%d%lf%d", &n, &p, &t);
  for (i = 1; i <= 2000; i++) {
    ans[i][0] = i;
    for (j = 1; j <= 2000; j++)
      ans[i][j] = ans[i][j - 1] * (1 - p) + ans[i - 1][j - 1] * p;
  }
  printf("%0.6lf", n - ans[n][t]);
  return 0;
}
