#include <cstdio>
#include <cstring>
#include <string>
#include <algorithm>
#include <cstdarg>
#include <list>
#include <cctype>
#include <queue>
using namespace std;
char str[23333];
int len ;
inline int next_int(int p){
  while(isdigit(str[p]))p++;return p;
}
int calc(int p){
  while(str[p] != ']' && p < len){
    if(str[p] == '['){
      p++;
      int x; sscanf(str+p, "%d", &x);
      p = next_int(p);
      for(int i = 1; i < x; i++)calc(p);
      p = calc(p);
    }else putchar(str[p++]);
  }
  return p+1;
}
int main(){
  freopen("passworda.in", "r", stdin);
  freopen("passworda.out", "w", stdout);
  scanf("%s", str);
  len = strlen(str);
  calc(0);
  return 0;
}