#include <keypad.h>
byte rows=5;
byte cols=3; 
char keys[rows][cols]={
   {'1','2','3'},
   {'4','5','6'},
   {'#','0','*',}
  
};
byte rpins[ROWS]={8,7,6,5};
byte cpins[COLS]={4,3,2};
keypad keypad =keypad(makekeymap(keys),rpins,cpins,rows,cols);
void setup() {
Serial.begin(9600);
}

void loop() {
 char key=keypad.getkey();
 if (key!=no_key)
 Serial.println(println(key));
}