#include <fstream>
#include <algorithm>
#include <cstring>
#include <cstdlib>
using namespace std;
ifstream fin("passworda.in");
ofstream fout("passworda.out");
string S,Ans;
int top=0,pos=0;
class STACK
{
public:
	int V,Multiple;
	string R;
}stack[20001];
void Initialize()
{
	fin>>S;
	S.insert(0,"[1");
	S.push_back(']');
}

string DFS()
{
int Ti;
string Q="\0";
	pos++;
	if('0'<=S[pos+1] && S[pos+1]<='9')
		Ti=(S[pos]-'0')*10+S[pos+1]-'0',pos+=2;
	else
		Ti=S[pos]-'0',pos++;
	while(S[pos]!=']')
	{
		while(S[pos]=='[')
			Q+=DFS();
		if(S[pos]==']')
			break;
		Q.push_back(S[pos]);
		pos++;
	}
string P=Q;
	for(int i=2;i<=Ti;i++)
		Q+=P;
	pos++;
	return Q;
}

int main()
{
	Initialize();
	
	fout<<DFS()<<endl;
	
	fin.close();
	fout.close();
	return 0;
}