#include <cstdio>
#include <vector>

int main() {
  int N;
  double p;
  scanf("%d %lf", &N, &p);

  std::vector<double> zaru(N+1, 1.0);
  double res = 0;
  for (int i = 2; i <= N; ++i) {
    res += zaru[i];
    for (int j = i+i; j <= N; j += i)
      zaru[j] *= 1-p;
  }

  for (int i = 2; i <= N; ++i)
    fprintf(stderr, "%2d: %.6f\n", i, zaru[i]);

  printf("%.12f\n", res);
}