./Main.java:14: error: cannot find symbol
			String ss=String.valueOf(i);
			                         ^
  symbol:   variable i
  location: class Main
./Main.java:16: error: variable j is already defined in method main(String[])
		for(int j=0;j<ch.length;j++)
		        ^
2 errors

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。