#include <bits/stdc++.h>
using namespace std;
int n, t;
double p;
double pr[2002][2002];
int main() {
  while (cin >> n >> p >> t) {
    pr[0][0] = 1.0;
    for (int i = 1; i <= t; ++i) {
      pr[i][0] = pr[i - 1][0] * (1.0 - p);
      for (int j = 1; j <= min(i, n); ++j) {
        if (j < n) {
          pr[i][j] = pr[i - 1][j - 1] * p + pr[i - 1][j] * (1.0 - p);
        } else {
          pr[i][j] = pr[i - 1][j - 1] * p + pr[i - 1][j];
        }
      }
    }
    double ans = 0.0;
    for (int i = 1; i <= n; ++i) {
      ans += pr[t][i] * (double)i;
    }
    printf("%.7lf\n", ans);
  }
  return 0;
}
