Kagami Mochi

An X-layered kagami mochi (X ≥ 1) is a pile of X round mochi (rice cake) stacked vertically where each mochi (except the bottom one) has a smaller diameter than that of the mochi directly below it. For example, if you stack three mochi with diameters of 10, 8 and 6 centimeters from bottom to top in this order, you have a 3-layered kagami mochi; if you put just one mochi, you have a 1-layered kagami mochi.

Lunlun the dachshund has N round mochi, and the diameter of the i-th mochi is d_i centimeters. When we make a kagami mochi using some or all of them, at most how many layers can our kagami mochi have?

Constraints

• 1 ≤ N ≤ 100
• 1 ≤ d_i ≤ 100
• All input values are integers.

Input

Input is given from Standard Input in the following format:

N d_1 : d_N

Output

Print the maximum number of layers in a kagami mochi that can be made.

Examples

Input

4 10 8 8 6

Output

3

Input

3 15 15 15

Output

1

Input

7 50 30 50 100 50 80 30

Output

4

inputFormat

input values are integers.

Input

Input is given from Standard Input in the following format:

N d_1 : d_N

outputFormat

Output

Print the maximum number of layers in a kagami mochi that can be made.

Examples

Input

4 10 8 8 6

Output

3

Input

3 15 15 15

Output

1

Input

7 50 30 50 100 50 80 30

Output

4

样例

7
50
30
50
100
50
80
30

4