#include<bits/stdc++.h>
using namespace std;

int main()
{
	int n=1,x=0,f=0;
	string s,a="";
	cin>>s;
	for(int i=0;i<s.size();i++)
	{
		if(s[i]=='['){
			f=1;
			cout<<a;
			a="";
			if(x)n*=x;
			x=0;
			continue;
		} 
		if(s[i]>='1'&&s[i]<='9')
		{
			x=x*10+s[i]-'0';
			continue;
		}
		if(s[i]==']'&&x!=0)
		{
			n*=x;
			for(int j=0;j<n;j++)
			{
				cout<<a;
			}
			x=0;n=1;a="";f=0;
			continue;
		}
		if(f==0&&s[i]>='A'&&s[i]<='Z')cout<<s[i];
		if(f==1&&s[i]>='A'&&s[i]<='Z')a+=s[i];
	}
}

数据太坑了