模拟：先看是否为负数，然后从后向前去除末尾的0最后将字符串反转即可

#include<iostream>
#include<algorithm>
using namespace std;
int main(){
    string s;
    cin>>s;
    if(s[0]=='-'){
        while(s.back()=='0'){
            s.pop_back();
        }
        reverse(s.begin()+1,s.end());
    }
    else{
        while(s.back()=='0')
            s.pop_back();
        reverse(s.begin(),s.end());
    }
    cout<<s<<endl;
    return 0;
}