#include<iostream> using namespace std; int main(){ int n,g=0,s=0,b=0,q=0,sum=0; cin>>n; g=n%10; s=n/10%10; b=n/100%10; q=n/1000%10; sum=q+b*10+s*100+g*1000; cout<<n-sum; return 0; }