#include <bits/stdc++.h>
using namespace std;
template <typename T>
void out(T x) {
  cout << x << endl;
  exit(0);
}
const int maxn = 2000 + 7;
int n;
long double p;
int t;
long double dp[maxn][maxn];
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> p >> t;
  dp[0][0] = 1.0;
  for (int i = 0; i < t; i++) {
    for (int j = 0; j < n; j++) {
      dp[i + 1][j] += (1.0 - p) * dp[i][j];
      dp[i + 1][j + 1] += p * dp[i][j];
    }
    dp[i + 1][n] += dp[i][n];
  }
  long double ans = 0.0;
  for (int i = 1; i <= n; i++) {
    ans += 1.0 * i * dp[t][i];
  }
  cout << fixed << setprecision(12) << ans << "\n";
  return 0;
}
