#include <stdio.h>

int main()
{
    double f, c;
    scanf("%lf", &f);
    c = 5*(f - 32)/9.0;
    printf("%.3lf\n", c);
    return 0;
}

#include<stdio.h>

int main()
{
    int a, b, c;
    scanf("%d%d%d", &a, &b, &c);
    double d = (a+b+c)/3.0;
    printf("%.3lf\n",d);
    return 0;
}

#include <stdio.h>

int main()
{
    int n=0, sum;
    while(n < 1 && scanf("%d", &n));
    sum = n*(1+n)/2;
    printf("%d\n", sum);
    return 0;
}

#include <stdio.h>
#include <math.h>
int main()
{
    const double pi = acos(-1.0); // pi使用acos(-1.0)求得M_PI不是ANSI C的标准
    int n =0;
    while( (n <1 || n > 359) && scanf("%d", &n) ); //1-359
    double th = n/180.0 * pi; //转换成弧度制
    printf("%lf %lf\n", sin(th), cos(th));
    return 0;
}

#include <stdio.h>

int main()
{
    int n = 0;
    double amount = 0;
    while( n < 1 && scanf("%d", &n) );
    if(n*95 >= 300)
        amount = n*95*0.85;
    else
        amount = n*95;
    printf("%.2lf\n", amount);
    return 0;
}

#include <stdio.h>

int main()
{
    int a = 0, b = 0, c = 0;
    while( (a * b *c < 1 && (a<1 || b<1 || c<1)) &&( scanf("%d%d%d", &a, &b, &c ) <= 3))
    {
        fflush(stdin);
    };
    if(!(a+b > c && a+c > b && b+c > a))
        printf("not a triangle\n");
    else
    { 
    if(a*a + b*b == c*c || a*a + c*c == b*b || b*b + c*c == a*a)
        printf("yes\n");
    else
        printf("no\n");
    }
    return 0;
}

#include <stdio.h>

int main()
{
    int y = 0;
    while(y <1 && scanf("%d", &y) <= 1)
    {
        fflush(stdin);
    }

    if((y%4 == 0 && y%100!=0 )|| (y % 400 == 0) )
    {
        printf("yes\n");
    }
    else
    {
        printf("no\n");
    }
    return 0;
}