#include<bits/stdc++.h>
using namespace std;
int main()
{
	int a[55];
	int b[25]={0};
	for(int i=0;i<50;i++)
	{
		cin>>a[i];
		b[a[i]]+=1;
	}
	int m=-1;
	for(int i=0;i<=19;i++)
	{
		if(b[i]>m)
		{
			m=b[i];
		}
	}
	cout<<m;
	return 0;
}
/**************************************************************
	Problem: 1180
	User: chenkexin
	Language: C++
	Result: Accepted
	Time:11 ms
	Memory:2072 kb
****************************************************************/