#include <iostream>
using namespace std;
long long int n, m, nrcif, z=1, primajum, douajum;
int main()
{
cin >> n;
m=n;
while (m>9)
{
++nrcif;
m/=10;
z*=10;
}
int k=nrcif/2;
for (m=1; m<=k; ++m)
z/=10;
douajum=n%z;
primajum=n/(z*10);
m=primajum*z+douajum;
cout << m;
}