https://www.cyberforum.ru/python-tasks/thread2994370.html

code2.java

import java.util.*;
import java.util.regex.*;

public class Main {
    public static void main(String args[]) {
      
      // init input
      final Scanner scan = new Scanner(System.in);
      
      // prompt strings
      System.out.print("Текст: ");
      final String text = scan.nextLine()/*.toLowerCase()*/;
      System.out.print("Строка: ");
      final String magic = scan.nextLine()/*.toLowerCase()*/;
      
      // generate regexs based
      // on the magic string
      ArrayList<String> regexs = new ArrayList<String>();
      regexs.add(magic);
      for (int i = 0; i < magic.length(); i++) {
          final StringBuilder sb = new StringBuilder(magic);
          sb.replace(i, i+1, "\\w");
          regexs.add(sb.toString());
      }
      
      // check all regexs
      ArrayList<Integer> results = new ArrayList<Integer>();
      for (String re : regexs) {
          Pattern p = Pattern.compile(re);
          Matcher m = p.matcher(text);
          while (m.find()) {
              results.add(m.start());
          }
      }
      
      // if there is no matches
      if (results.size() == 0) {
          System.out.println(-1);
          System.exit(0);
      }
      
      // otherwise
      System.out.println(Collections.min(results));
    }
}