#include <bits/stdc++.h>
using namespace std;
double dp[2005][2005][2];
int main() {
  int n, t;
  double p;
  while (~scanf("%d%lf%d", &n, &p, &t)) {
    memset(dp, 0, sizeof(dp));
    dp[0][0][0] = 1;
    for (int i = 1; i <= t; i++) {
      for (int j = 0; j <= n; j++) {
        dp[i][j][0] = (dp[i - 1][j][0] + dp[i - 1][j][1]) * (1 - p);
        dp[i][j][1] = (dp[i - 1][j - 1][0] + dp[i - 1][j - 1][1]) * p;
      }
    }
    double ans = 0;
    for (int i = 1; i <= t; i++) ans += dp[i][n][1] * n;
    for (int i = 1; i < n; i++) {
      ans += dp[t][i][0] * i;
      ans += dp[t][i][1] * i;
    }
    printf("%lf\n", ans);
  }
}
