C++ :

#include<bits/stdc++.h>
using namespace std;
int n,s,t;
int work(int x)
{
	int ans=0;
	int sum=x/11*5;
	int t=x%11;
	int sum1=0;
	int s[]={0,0,1,1,0,0,1,0,1,0,0,1};
	for(int i=1;i<=t;i++)
		sum1+=s[i];
	return sum1+sum;	 
}
int main()
{	
	cin>>n>>s>>t;
	cout<<work(t)-work(--s);
    return 0;
}