---

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

int main(void) {
    double x;

    if (scanf("%lf", &x) != 1 || x == 0) {
        printf("n/a");
    } else {
        double y = 7e-3 * pow(x, 4) +
                   ((22.8 * cbrt(x) - 1000.0) * x + 3.0) /
                   (x * x / 2.0) -
                   x * pow(10.0 + x, 2.0 / x) -
                   1.01;

        printf("%.1lf", y);
    }

    return 0;
}