import java.util.HashMap;

import java.util.Hashtable;

public class Test159 {

public static int lengthOfLongestSubstringTwoDistinct(String s) {

Hashtable<Character,Integer> hm = new Hashtable<Character,Integer>();

int len = s.length();

int j = 0;

int maxlen = 0;

int curDistinctCount=0;

for(int i =0; i < len; i++){

if(hm.get(s.charAt(i))==null || hm.get(s.charAt(i))==0){

hm.put(s.charAt(i), 1);

curDistinctCount++;

} else {

hm.put(s.charAt(i), hm.get(s.charAt(i))+1);

}

if(curDistinctCount<=2){

maxlen = Math.max(maxlen, i-j+1);

} else {

while(j<s.length() && hm.get(s.charAt(j))!=null && hm.get(s.charAt(j))!=1){

hm.put(s.charAt(j),hm.get(s.charAt(j))-1);

j++;

}

if(j>=len) break;

hm.put(s.charAt(j),0);

curDistinctCount--;

j++;

}

}

return maxlen;

}

static int sum(int a, int b){

int c = a + b;

return c;

}

public static void main(String[] args) {

String s = "aaabc";

//int ret =lengthOfLongestSubstringTwoDistinct(s);

int result = sum(1,3);

System.out.println(result);

//System.out.println(ret);

}

}