#include<bits/stdc++.h>
using namespace std;
char s[20010];
int a;
int main(){
	int i = 1;
	while(1){
		cin >> s[i];
		if (s[i] == ']'){
			break;
		}
		if(s[i] != '[' && s[i] != ']'){
			cout << s[i];
		}else{
			cin >> a;
			for (int j = 1; j <= a; j++){
				cin >> s[j];
			}
			for (int j = 1; j <= a; j++){
				for (int k = 1; k <= a; k++){
					cout << s[k];
				}
			}
		}
		i++;
	}
	return 0;
}
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我的这个代码为什么爆零？？？？？？？？