Untitled

#include <bits/stdc++.h>
#define endl '\n'
#define maxn 1005
#define TASK bai1
#define For(i,a,b) for ( int i = a; i <= b; i++ )
#define Ford(i,a,b) for ( int i = a; i >= b; i-- )
#define MOD 10000000

using namespace std;

string n ;

string Ret(string x) {
    string y = "" ;
    Ford(i,x.size()-1,0) y += x[i] ;
    return y;
}

string Mi(string x) {
    if ( x == Ret(x)) return x;
    long long a = stoll(x) + stoll(Ret(x)) ;
    x = to_string(a) ;
    return Mi(x) ;
}

void inp() {
     cin >> n;
}

void solve() {
    long long a = stoll(n) + stoll(Ret(n)) ;
    n = to_string(a) ;
    cout << Mi(n) ;
}
int main()
{
    ios_base:: sync_with_stdio(0);
    cin.tie(0);
    if(fopen("bai1.inp","r")){
        freopen("bai1.inp","r",stdin);
    }
    inp();
    solve() ;
}