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