#include <iostream>
#include <string>
using namespace std;
string ex(){
string s="",X;
char c;int D;
while(cin>>c){
if(c=='['){
cin>>D;
X=ex();
while(D--){
s+=X;
}
}
else if(c==']'){
return s;
}
else{
s+=c;
}
}
return s;
}
int main(){
cout<<ex();
return 0;
}
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