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#include <iostream>
#include <algorithm>
using namespace std;
int n;
int main(){
int n,ans;
cin>>n;
for(int i =0;i<=n/5;i++){
int j=(n-7i)/4;
int k=n-i-j;
if(j>=0&&k%3==0 && (n-7i)%4==0){
ans++;
}

}
cout<<ans;                        

return 0;

}