#include <bits/stdc++.h>
using namespace std;
template <typename T>
T gcd(T x, T y) {
  while (y > 0) {
    x %= y;
    swap(x, y);
  }
  return x;
}
template <class _T>
inline _T sqr(const _T &x) {
  return x * x;
}
template <class _T>
inline string tostr(const _T &a) {
  ostringstream os("");
  os << a;
  return os.str();
}
const long double PI = 3.1415926535897932384626433832795L;
template <typename T>
inline void input(T &a) {
  static int c;
  a = 0;
  while (!isdigit(c = getchar()) && c != '-') {
  }
  char neg = 0;
  if (c == '-') {
    neg = 1;
    c = getchar();
  }
  while (isdigit(c)) {
    a = 10 * a + c - '0';
    c = getchar();
  }
  if (neg) a = -a;
}
template <typename T = int>
inline T nxt() {
  T res;
  input(res);
  return res;
}
const int N = 2000;
long double dp[N + 1][N + 1];
inline void solve() {
  int n, t;
  double p;
  cin >> n >> p >> t;
  dp[0][0] = 1;
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < t; ++j) {
      dp[i][j + 1] += dp[i][j] * (1 - p);
      dp[i + 1][j + 1] += dp[i][j] * p;
    }
  }
  for (int j = 0; j < t; ++j) {
    dp[n][j + 1] += dp[n][j];
  }
  double ans = 0;
  for (int i = 0; i <= n; ++i) {
    ans += i * dp[i][t];
  }
  cout << setprecision(10) << fixed << ans << endl;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  solve();
  return 0;
}
