Hangman 2 Player Game - User Cannot Guess More Than 6 Times

I am creating a hangman code. So the game i am creating is 2 player, first player enters the word and second player guesses. i made the code but i don't know how to restrict the first player from adding random characters into the secret word because for my project the word can only contain letters. so i need making the code so the player 1 can only enter letters.

My code is below:

/**
* Auto Generated Java Class.
*/
import java.util.Scanner;
public class Hangman {
public static void main(String[] args) {
Scanner input= new Scanner(System.in);
String player1,player2;
int wrongguessamount = 0; //keeps the count of the amount of wrong guesses
int correctguessamount = 0; //keeps count of the amount of correct guesses
int maxincorrect=6;//makes sure the user cant guess more than 6 times

[Code] .....