题解:简单的数括号问题……
#include
char s[1005];
int main(){while(scanf("%s",s)!=EOF){int top=0;for(int i=0;;i++){if(s[i]=='B')break;if(s[i]=='(')top++;if(s[i]==')')top--;}printf("%d\n",top);}return 0;
}