# Remove Duplicates from Sorted Array
# Given a sorted array nums, remove the duplicates in-place such that each
# element appear only once and return the new length.
# Do not allocate extra space for another array, you must do this by modifying the 
# input array in-place with O(1) extra memory.

# Example 1:
# Given nums = [1,1,2],
# Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively.
# It doesn't matter what you leave beyond the returned length.

# Example 2:
# Given nums = [0,0,1,1,1,2,2,3,3,4],
# Your function should return length = 5, with the first five elements of 
# nums being modified to 0, 1, 2, 3, and 4 respectively.
# It doesn't matter what values are set beyond the returned length.

def removeDuplicates(nums):
    i=0
    while i < len(nums) - 1:
        if nums[i] == nums[i+1]:
            nums.remove(nums[i])
        else:
            i+=1
    return len(nums)
    
if __name__ == "__main__":
	nums = list(map(int, input().split()))
	r = removeDuplicates(nums)
	print(r)
	
# Remove Duplicates from Sorted Array
# Given a sorted array nums, remove the duplicates in-place such that each
# element appear only once and return the new length.
# Do not allocate extra space for another array, you must do this by modifying the 
# input array in-place with O(1) extra memory.

# Example 1:
# Given nums = [1,1,2],
# Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively.
# It doesn't matter what you leave beyond the returned length.

# Example 2:
# Given nums = [0,0,1,1,1,2,2,3,3,4],
# Your function should return length = 5, with the first five elements of 
# nums being modified to 0, 1, 2, 3, and 4 respectively.
# It doesn't matter what values are set beyond the returned length.

def removeDuplicates(nums):
    i=0
    while i < len(nums) - 1:
        if nums[i] == nums[i+1]:
            nums.remove(nums[i])
        else:
            i+=1
    return len(nums)
    
if __name__ == "__main__":
	nums = list(map(int, input().split()))
	r = removeDuplicates(nums)
	print(r)
	
# Remove Duplicates from Sorted Array # Given a sorted array nums, remove the duplicates in-place such that each # element appear only once and return the new length. # Do not allocate extra space for another array, you must do this by modifying the # input array in-place with O(1) extra memory. # Example 1: # Given nums = [1,1,2], # Your function should return length = 2, with the first two elements of nums being 1 and 2 respectively. # It doesn't matter what you leave beyond the returned length. # Example 2: # Given nums = [0,0,1,1,1,2,2,3,3,4], # Your function should return length = 5, with the first five elements of # nums being modified to 0, 1, 2, 3, and 4 respectively. # It doesn't matter what values are set beyond the returned length.