#include <bits/stdc++.h> using namespace std; string s; stack<char> sta; int main() { cin>>s; for(int i=0;i<s.size();i++) { if(s[i]=='('||s[i]=='[') sta.push(s[i]); else if(s[i]==')'||s[i]==']') { if(!sta.empty()) { char top = sta.top(); // 检查栈顶元素与当前右括号是否匹配 if((top == '(' && s[i] == ')') || (top == '[' && s[i] == ']')) sta.pop(); } else {cout<<"false"; return 0;} } else continue; } if(sta.empty()) cout<<"true"; else cout<<"false"; return 0; }