#include <stdio.h>

void main()
{
 int a = 2;
 int b = 5;
 printf( "a=%d, b=%d\n", a, b );
 switch( a % 2 ){
 case 0:
  if ( b % 2 == 0 )
   printf( "A:偶数 B:偶数\n" );
  else
  {
   printf("A:偶数 ");
 case 1:
   if ( b % 2 == 0 )
    printf( "B:偶数\n" );
   else
    printf( "B:奇数\n" );
  }
 }
}