Codeforces 556A case of the Zeros and Ones (elimination 01)

Time limit:1000MS Memory Limit:262144KB 64bit IO Format:%i64d &%i6 4u  

Description

Andrewid The Android is a galaxy-famous detective. In the He free time he likes to think about strings containing zeros and ones.

Once he thought about a string of length n consisting of zeroes and ones. Consider the following operation:we choose any of the adjacentpositions in the string, and if one them contains 0, and T He other contains 1, then we is allowed to remove these and digits from the string, obtaining a string of length N -2 as a result.

Now Andreid thinks on what's the minimum length of the string that can remain after applying the described Operation s Everal Times (possibly, zero)? Help him to calculate this number.

Input

First line of the input contains a single integer n (1≤ n ≤2 10^{5), the length of the Stri ng that Andreid have.}

The second line contains the string of length n consisting only from zeros and ones.

Output

Output the minimum length of the string that is remain after applying the described operations several times.

Sample Input

Input

4
1100

Output

0

Input

5
01010

Output

1

Input

8
11101111

Output

6

Hint

In the first sample test it's possible to change the string like the following:.

In the second sample test it's possible to change the string like the following:.

In the third sample test it's possible to change the string like the following:.

Puzzle: Look at the number of 0 and 1 in the string, subtract

#include <cstdio>#include<cstring>intn,p,q;Chara[200000];intMain () {scanf ("%d",&N); scanf ("%s",&a); Q=0, p=0;  for(intI=0; i<n; i++)    {        if(a[i]=='1') P++; if(a[i]=='0') Q++; }    if(p>=q) printf ("%d", P-q); Elseprintf ("%d", Q-p); return 0;}

Codeforces 556A case of the Zeros and Ones (elimination 01)