#include <bits/stdc++.h>
using namespace std;
inline int sn() {
  int n = 0;
  int ch = getchar();
  while (ch < 48) ch = getchar();
  while (ch > 47) n = (n << 3) + (n << 1) + ch - '0', ch = getchar();
  return n;
}
double dp[2005][2005];
int main() {
  int i, j, n, t;
  double p;
  scanf("%d %lf %d", &n, &p, &t);
  dp[0][0] = 1;
  for (i = 1; i <= t; i++) {
    dp[i][0] = pow(1 - p, i);
    dp[i][n] = dp[i - 1][n] + dp[i - 1][n - 1] * p;
    for (j = 1; j <= n - 1; j++) {
      dp[i][j] = dp[i - 1][j] * (1 - p) + dp[i - 1][j - 1] * p;
    }
  }
  double ans = 0;
  for (i = 1; i <= n; i++) {
    ans = ans + i * dp[t][i];
  }
  printf("%0.6lf ", ans);
  return 0;
}
