int main()

{

int x=1,y=0;

if(!x) y++;

 else if(x==0) 

if (x) y+=2;

 else y+=3;

 printf("%d\n",y); 

return 0；

}

void main( )

{ char ch;

ch=getchar( );

switch(ch)

{ case 'H': printf("Hello!\n");

  case 'G': printf("Good morning!\n"); 

  default: printf("Bye_Bye!\n");  }

 }  

int x=0,s=0;

while (!x!=0) s+=++x;

printf("%d",s);

void main()

{ int x,i;

for(i=1;i <=50;i++)

{ x=i;

if(x%2==0)

if(x%3==0)

if(x%7==0)

printf("%d",i);

}

}