#include <bits/stdc++.h>
using namespace std;
const long long N = 1e5;
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long n, t;
  long double p;
  cin >> n >> p >> t;
  long double dp[n + 1];
  memset(dp, 0.0, sizeof(dp));
  dp[0] = 1.0;
  for (long long i = 0; i < t; i++) {
    for (long long j = n; j >= 0; j--) {
      dp[j] =
          ((j - 1 < 0) ? 0 : dp[j - 1] * p) + dp[j] * ((j == n) ? 1 : (1 - p));
    }
  }
  long double ans = 0;
  for (long long i = 0; i <= n; i++) ans += i * dp[i];
  cout << fixed << setprecision(12);
  cout << ans << '\n';
}
