#include "key.h"
unsigned char Key_Read() {
  unsigned char temp = 0;
  ET1 = 0;

  P44 = 0;
  P42 = 1;
  P35 = 1;
  P34 = 1;
  if (P33 == 0) temp = 4;
  if (P32 == 0) temp = 5;
  if (P31 == 0) temp = 6;
  if (P30 == 0) temp = 7;

  P44 = 1;
  P42 = 0;
  P35 = 1;
  P34 = 1;
  if (P33 == 0) temp = 8;
  if (P32 == 0) temp = 9;
  if (P31 == 0) temp = 10;
  if (P30 == 0) temp = 11;

  P44 = 1;
  P42 = 1;
  P35 = 0;
  P34 = 1;
  if (P33 == 0) temp = 12;
  if (P32 == 0) temp = 13;
  if (P31 == 0) temp = 14;
  if (P30 == 0) temp = 15;

  P44 = 1;
  P42 = 1;
  P35 = 1;
  P34 = 0;
  if (P33 == 0) temp = 16;
  if (P32 == 0) temp = 17;
  if (P31 == 0) temp = 18;
  if (P30 == 0) temp = 19;

  P3 = 0xff;
  ET1 = 1;
  return temp;
}