#include <bits/stdc++.h>
using namespace std;
const long long mod = 998244353;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long n, t;
  long double p;
  cin >> n >> p >> t;
  n = min(n, t);
  vector<vector<long double>> dp(t + 1, vector<long double>(n + 1, 0.00));
  dp[0][0] = 1.00;
  for (long long i = (long long)0; i != (long long)t; i = i + 1) {
    long long mx = min(i, n - 1) + 1;
    for (long long j = (long long)0; j != (long long)mx; j = j + 1) {
      dp[i + 1][j] += dp[i][j] * (1.00 - p);
      dp[i + 1][j + 1] += dp[i][j] * (p);
    }
    dp[i + 1][n] += dp[i][n];
  }
  long double ans = 0;
  for (long long i = (long long)1; i != (long long)n + 1; i = i + 1) {
    ans += (long double)i * dp[t][i];
  }
  cout << fixed << setprecision(8) << ans << '\n';
}
