#include <bits/stdc++.h>
using namespace std;
void solve() {
  long long n, t;
  long double p;
  cin >> n >> p >> t;
  long long i, j;
  long double res = 0;
  long double dp[n + 1][t + 1];
  memset(dp, 0, sizeof(dp));
  dp[0][0] = 1;
  for (i = 0; i <= n; i++) {
    for (j = 0; j < t; j++) {
      if (i == n) {
        dp[i][j + 1] += dp[i][j];
      } else {
        dp[i + 1][j + 1] += dp[i][j] * p;
        dp[i][j + 1] += dp[i][j] * (1 - p);
      }
    }
  }
  for (i = 0; i <= n; i++) {
    long double tans = i * dp[i][t] * 1.0;
    res += tans;
  }
  cout << res << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  if (fopen("input.txt", "r")) {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
  }
  cout << setprecision(20);
  long long t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
