#include<stdio.h>
int main()
{

int x;

printf("输入一个整数:\n");
scanf("%d",&x);

if(x%2==1)
printf("是奇数"); 
else
printf("是偶数");

return 0 ;

} 

#include <stdio.h>
int main() {
int days;
printf("输入一个整数: \n");
scanf("%d",&days);
if(1<=days<=5) 
printf("workdays, fighting\n");
else if(6<=days<=7)
printf("weekend, relax~\n");
else
printf("Ooops, not in 1~7\n");
return 0;
}

#include<stdio.h>
int main()
{
    char ch;

    printf("输入一个字符：\n");
    scanf("%c",&ch);
    
    if(65<=ch<=90)
        ch=ch-'a'+'A';
        
        printf("%c\n",ch);
        
        return 0; 
}

#include<stdio.h> 
int main()
{
    
printf("201983270541");

return 0;

}

#include <stdio.h>
int main()
{
printf("Hello, Mars!");
return 0;
}

#include<stdio.h>
int product(int,int);
int main()
{
    int x,y,s;
    scanf("%d%d",&x,&y);
    s = product(x,y);
    printf("The mul is:%d",s);
    return 0;
}
int product(int a,int b)
{
    int mul;
    mul=a*b;
    return mul;
}