include [HTML_REMOVED]

include [HTML_REMOVED]

include [HTML_REMOVED]

using namespace std;

//操作符优先级
int priority(char op){
if(op == ‘+’ || op == ‘-‘)
return 1;
else if(op == ‘*’ || op == ‘/’)
return 2;
else return 0;
}

string infixToPostfix(string infix){
stack[HTML_REMOVED] st;
string postfix;

for(auto c : infix){
    if(c == ' ') continue;
    if(c >= 'A' && C <= 'Z' || c >='a' && c <= 'z')
    postfix += c;
    else if(c == '(') st.push(c);
    else if(c == ')'){
        while(!st.empty() && st.top() != '('){
            postfix += st.top();
            st.pop();
        }
        if(st.empty())  return "Invalid Expression"; 
        st.pop()
    }
    else{//运算符的情况
        while(!st.empty() && priority(c) <= priority(st.top())){
            postfix += st.top();
            st.pop();            
        }
        st.push(c);
    }
}
while(!st.empty()){
    if(st.top() == '(') return "Invalid Expression";
    postfix += st.top();
    st.pop()
}

}

int main() {
string infix;
cin >> infix;
string postfix = infixToPostfix(infix);
cout << postfix << endl;

return 0;

}