/*数组循环输入输出*/
#include <stdio.h>
int main()
{
    int num[1024], n;

    scanf("%d", &n); //要输入元素的个数
    for (int i = 0; i < n; i++)
        scanf("%d", &num[i]); //循环输入元素

    for (int i = 0; i < n; i++)
        printf("%d ", num[i]); //遍历数组输出元素
}
/*圆柱体的表面积*/
#include <stdio.h>
#include <math.h>
int main()
{
    const double pi = acos(-1.0);
    //const定义常量pi,acos(-1.0)求π的值
    double r, h, s1, s2, s;
    scanf("%lf%lf", &r, &h);
    s1 = pi * r * r;
    s2 = 2 * pi * r * h;
    s = s1 * 2.0 + s2;
    printf("Area = %.3f\n", s);
    return 0;
}
/*
圆柱体表面积=底面积*2+侧面积
底面积=πr^2
侧面积=2πrh
*/
/*交换变量-1*/
#include <stdio.h>
int main()
{
    int a, b, t;
    scanf("%d%d", &a, &b);
    t = a;
    a = b;
    b = t;
    printf("%d %d\n", a, b);
    return 0;
}
/*交换变量2*/
#include <stdio.h>
int main()
{
    int a, b;
    scanf("%d%d", &a, &b);
    a = a + b;
    b = a - b;
    a = a - b;
    printf("%d %d", a, b);
    return 0;
}
/*
a=a0,b=b0;
a=a+b:a0+b0,b=b0;
b=a-b:a0+b0,b=a0;
a=a-b:a=b0,b=a0;
*/
/*交换变量-3*/
#include <stdio.h>
int main()
{
    int a, b;
    scanf("%d%d", &a, &b);
    printf("%d %d", b, a);
    return 0;
}