#import <Foundation/Foundation.h>
        
int main( int argc, const char * argv[ ] )
{
   /* local variable definition */
   int a = 20;

   /* do loop execution */
   do {
       NSLog(@"value of a: %d\n", a);
       a = a+1;
   }while( a < 20 );
 
   return 0;
}