Problem:
Score : 200 points

Problem Statement

You have an integer variable x.
Initially, x=0.

Some person gave you a string S of length N, and using the string you performed the following operation N times.
In the i-th operation, you incremented the value of x by 1 if S_i=I, and decremented the value of x by 1 if S_i=D.

Find the maximum value taken by x during the operations (including before the first operation, and after the last operation).

Constraints

1≤N≤100

|S|=N

No characters except I and D occur in S.

Input

The input is given from Standard Input in the following format:

N
S

Output

Print the maximum value taken by x during the operations.

Sample Input 1

5
IIDID

Sample Output 1

2

After each operation, the value of x becomes 1, 2, 1, 2 and 1, respectively. Thus, the output should be 2, the maximum value.

Sample Input 2

7
DDIDDII

Sample Output 2

0

The initial value x=0 is the maximum value taken by x, thus the output should be 0.

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
int main(){
int n;
char s[1000];
int i;
int x=1;
int o=0;
int k[100];
int u;
int y;
int temp;
scanf("%d%s",&n,s);
for(i=0;i<n;i++){
	if(s[i]=='I'){
		++x;k[o]=x;
		o++;
	}else if(s[i]=='D'){
		--x;
		k[o]=x;
		o++;
	}
	
}
for(u=0;u<=o;u++){
	for(y=o;y>u;y--){
		if(k[y]>k[y-1]){
			temp=k[y];
			k[y]=k[y-1];
			k[y]=k[y-1];
			
			
		}
	}
}
printf("%d",k[0]);
	return 0;
}