public static void main(String[] args) {
	Scanner scanner=new Scanner(System.in);
	String string=scanner.nextLine();
	int count=0;
	int max=0;
	int l=0,r=0;
	for (int i = 0; i < string.length()-1; i++) {
		count=0;
		if (string.charAt(i)=='('&&string.charAt(i+1)==')') {
			count++;
			if (count>max) {
				max=count;
			}
			l=i-1;
			r=i+1;
			while(l>=0&&r<string.length()) {
				if (string.charAt(l)=='('&&string.charAt(r)==')'){
					count++;
					if (count>max) {
						max=count;
					}
				}else{
					break;
				}
				l--;
				r++;
			}
		}
	}
	System.out.println(max);
}