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

};
byte rowPins[Rows]={5,4,3,2};
byte colPins[cols]={9,8,7,6};
Keypad customKeypad=Keypad(makeKeymap(hexaKeys),rowPins,colPins,Rows,cols);

void setup() {
  // put your setup code here, to run once:
   Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
    char customKey=customKeypad.getKey();
    if(customKey){
      Serial.println(customKey);
    }
}