((((B)()))()) (B)
4 1
#include<stdio.h>
#include<string.h>
char s[1001];
int main(){
while(~scanf("%s",s)){
int len=strlen(s),num=0;
for(int i=0;i<len;++i){
if(s[i]=='B')
break;
if(s[i]=='(')
num++;
else num--;
}
printf("%d\n",num);
}
return 0;
}原文：http://blog.csdn.net/qq_18062811/article/details/44679307