#include <queue>
#include <iostream>
#include <algorithm>
using namespace std;
int main ()
{
    priority_queue<int,vector<int>,greater<int> > pq;
    int n,x,sum=0;
    for(int i=0;i<10;i++)
    {
        cin>>x;
        pq.push(x);
    }
    cin>>x;
    while(pq.size()>1)
    {
        if(x+30>=pq.top())
            sum++;
        else
            break；
        pq.pop();
    }
    cout<<sum;
    return 0;
}