#include <Keypad.h>
const uint8_t ROW =4 ;
const uint8_t CLMN =4 ;
char keys[ROW][CLMN]={{'1','2','3','A'},
                      {'4','5','6','B'},
                      {'7','8','9','C'},
                      {'*','0','#','D'}};


const uint8_t rowpin[ROW]={9,8,7,6};
const uint8_t clmpin[CLMN]={5,4,3,2};

Keypad keypad =(keypad)(makeKeymap(keys),rowpin,clmpin,ROW,CLMN);

void setup(){
  Serial.begin(9600);

}
void loop(){
  char key=keypad.getKey();//capital K

  if(key!=NO_KEY)
  Serial.println(key);
}