#include <avr/io.h>          
  
  int main(void) 
  {
    
    ddrb = 0xff;        
    ddrc = 0x00;        
  
    while(1)
    {
      if ((pinc &0b00100000))  
        portb = 0x55;    
      else
        portb = 0xaa;
    } 
  
    return 0;
  }