parajuliamit

void main(){
  String val = "31208345654312309845312345654321";
  String longest = val.substring(0,3);
  
  for(int i = 0 ; i< val.length; i++){
    for(int j = 3; j <= val.length-i; j++){
      String testString = val.substring(i,j+i);
      if(reverseString(testString) == testString){
      if(testString.length >= longest.length){
        longest = testString;