#include "iostream" #include "string" #include "stdio.h" #include "ctype.h" #include "algorithm" #include "stack" using namespace std; int cacluExprePriority(string str,bool &hasC) { int left=0; int right=0; bool bfind=false; for(int i=0;i<str.size();i++) { if(str[i]=='(') left++; if(str[i]==')') right++; if(str[i]=='/') hasC=true; if(str[i]=='*'||str[i]=='/') { if(left==right) return 2; } if(str[i]=='+'||str[i]=='-') { bfind=true; } } return bfind?1:-1; } bool vis[1000]; int safe(int i,int n) { if(i<0) return 0; if(i>=n) return n-1; return i; } void findIndexOfBrackets(string str) { stack<int>q; for(int i=0;i<str.size();i++) { if(str[i]=='(') { q.push(i); } if(str[i]==')') { int s=q.top(); int t=i; bool hasC=false; int priority=cacluExprePriority(str.substr(s+1,t-s-1),hasC); q.pop(); bool temp=false; if(s-1>=0&&cacluExprePriority(str.substr(safe(s-1,str.size()),1),temp)>=cacluExprePriority(str.substr(safe(t+1,str.size()),1),temp)) { char op=str[s-1]; { if(op=='+') { vis[s]=vis[t]=true; } if(op=='-') { if(priority==2) vis[s]=vis[t]=true; } if(op=='*') { if(priority==2&&hasC==false) vis[s]=vis[t]=true; } } } else if(t+1<str.size()) { char op=str[t+1]; if(op=='+'||op=='-') { vis[s]=vis[t]=true; } if(op=='*'||op=='/') { if(priority==2) vis[s]=vis[t]=true; } } } } } int main() { string exper; cin>>exper; findIndexOfBrackets(exper); for(int i=0;i<exper.size();i++) if(vis[i]==false) cout<<exper[i]; cout<<endl; return 0; }