#include<iostream> using namespace std; int main() { /* int n,s=1,i; cin>>n; for(i=0;i<n-1;i++){ s+=i; } cout<<s; */ int n,s=10000,i,j; cin>>n; if(n%2==1){ cout<<s-(n/2)*1; }else{ cout<<s-(n/2-1)*2; } return 0; }