import java.util.*;

/**
 * Template code to help you parse the standard input
 * according to the problem statement.
 **/
class Solution {
    
    public static void main( String[] args ) {
        // hint: read values via Scanner methods
        var scanner = new Scanner( System.in );
        
        // code your solution here
        Map<String, Integer> lastOccurrences = new HashMap<>();
        
        int startIndex = 0;
        int maxLength  = 0;
        int index      = 0;
        
        while ( scanner.hasNext() ) {
            Integer previousOccurrence = lastOccurrences.put( scanner.next(), index++ );
            if ( previousOccurrence != null ) {
                if ( previousOccurrence >= startIndex ) {
                    maxLength  = Math.max( maxLength, index - 1 - startIndex );
                    startIndex = previousOccurrence + 1;
                }
            }
        }
        maxLength = Math.max( maxLength, index - startIndex );
        
        // Write result with System.out.println()
        System.out.println( maxLength );
    }
}