int arr[100];
int number,newNumber,index,digit,count;
cin>>number;
while(number!=0)
{
digit=number%10;
number/=10;
index++;
if(index%2!=0)
{
arr[count]=digit;
count++;
}
}
for(int i=count-1;i>=0;i--)
{
newNumber+= pow(10,i) * arr[i];
}
cout<<newNumber;