代码

#include <iostream>
#include <cmath>
using namespace std;

int read()
{
	char a;
	int sum=0;
	a=getchar();
	while(a<'0'||a>'9') a=getchar();
	while(a>='0'&&a<='9') 
	sum*=10,sum+=(a-'0'),a=getchar();
	return sum;
}

int digui()
{
	int sum=0;
	char a;
	while(cin>>a)
	{
		if(a=='F')
		{
			cin>>a;
			sum+=read();
		}
		else if(a=='B')
		{
			cin>>a;
			sum-=read();
		}
		else if(a=='R')
		{
			for(int i=0;i<5;i++) cin>>a;
			sum+=(read()*digui());
		}
		else if(a==']')
		{
			break;
		}
	}
	return sum;
}

int main()
{
	cout<<abs(digui());
	return 0;
}