#include<iostream> using namespace std; int main(){ int money,y1,y2,y5,total=0; cin>>money; money=money*100; for(int i=1;i<=money/5-1;i++){ int left=money-5*i; if(i%2==1) total=left/2; else total+=left/2-1; } cout<<total; return 0; }