#include<stdio.h>
union Distance{
    float km;
    float mi;
};
int main(){
    int choice;
    float distance;
    union Distance d;
    scanf("%d\n%f",&choice,&distance);
    if(choice==1 && distance>=0){
        d.mi=distance*0.621371;
            printf("%.2f",d.mi);
    } else if(choice==2 && distance>=0){
            d.km=distance/0.621371;
            printf("%.2f",d.km);
      else {
                printf("Invalid input");
            }
    return 0;
}