#include <stdio.h>
#include <math.h>

int main() {
    int P, Q;
    scanf("%d", &P);
    scanf("%d", &Q);

    double ok = 1.0, ng = 1e12;
    for (int i = 0; i < 60; i++) {
        double N = (ok + ng) / 2;
        if (N * N <= Q * log2(N) * N + P) {
            ok = N;
        } else {
            ng = N;
        }
    }
    printf("%f\n", ok);

    return 0;
}