import java.util.Scanner;

public class SwitchingLetters {

public static void main(String[] args) {

Scanner keyboard = new Scanner(System.in);

System.out.println("Please enter two numbers:");

int index1 = keyboard.nextInt() - 1;

int index2 = keyboard.nextInt() - 1;

keyboard.nextLine();

System.out.println("Please enter a sentence:");

String sentence = keyboard.nextLine();

System.out.println("The new sentence:\n" + switchLetters(index1, index2, sentence));

}

/* Switches letters according to given indexes. */

public static String switchLetters(int index1, int index2, String sentence) {

return sentence.substring(0,index1) + sentence.charAt(index2) + sentence.substring(index1 + 1, index2) + sentence.charAt(index1) + sentence.substring(index2 + 1, sentence.length());

}

}