import java.util.Scanner;
import java.util.Arrays;
public class Main {
private static int getPopulation(int k, int n) {
if( k == 0 ) return n;
int population = 0;
for(int i=1; i<=n; i++) {
population += getPopulation(k-1, i);
}
return population;
}
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int[] counts = new int[9];
String str = String.valueOf(n);
char[] nums = str.toCharArray();
for(int i=0; i<nums.length; i++) {
int temp = nums[i] - '0';
if( temp == 9 ) temp = 6;
counts[temp]++;
}
counts[6] = (int) Math.ceil(counts[6] / 2.0);
int max = 0;
for( int i=0; i<counts.length; i++ ) {
if( counts[i] > max ) max = counts[i];
}
System.out.println( max );
}
}
<?php
$num = rtrim(fgets(STDIN));
$arr = count_chars($num);
$arr[ord('6')] = $arr[ord('9')] = intdiv( $arr[ord('6')]+$arr[ord('9')]+1, 2 );
echo max($arr);
num = input()
A = [num.count(str(i)) for i in range(10)]
A[6] = A[9] = (A[6]+A[9]+1)//2
print(max(A))