#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int n,i=10000,j=10000,k; cin>>n; for( k=1;k<=(n-1)/2;k++){ i--; j-=2; } if(n%2) cout<<i<<endl; else cout<<j<<endl; return 0; }