#include <stdio.h>
#include <stdlib.h>

int main()
{
    float radius, circumference; 
    
    printf("½Ð¿é¤J¥b®|(cm)¡G");
    scanf("%f", &radius);
    
    circumference = 2.0 * 3.1416 * radius;
    
    printf("The circumference of the circle is %f \n", circumference);
    
    system("PAUSE");
    return 0;    
}