#include <stdio.h>

int main() {
    double val;
    while (scanf("%lf", &val) != EOF) {
        double i = 0;
        if(val >= 0) {
            if(val < 1){
                while(i * i * i < val) {
                    i += 0.01;
                }
            }else {
                i = 1;
                while(i * i * i < val) {
                    i += 0.01;
                }
            }
            
        } else {
            if(val > -1) {
                while(i * i * i > val) {
                    i -= 0.01;
                }
            }
            else {
                i = -1;
                while(i * i * i > val) {
                    i -= 0.01;
                }
            }
        }
        printf("%.1lf\n", i);
    }
    return 0;
}