The recent All-Berland Olympiad in Informatics featured n participants with each scoring a certain amount of points.

As the head of the programming committee, you are to determine the set of participants to be awarded with diplomas with respect to the following criteria:   At least one participant should get a diploma.  None of those with score equal to zero should get awarded.  When someone is awarded, all participants with score not less than his score should also be awarded. 

Determine the number of ways to choose a subset of participants that will receive the diplomas.


-----Input-----

The first line contains a single integer n (1 ≤ n ≤ 100) — the number of participants.

The next line contains a sequence of n integers a_1, a_2, ..., a_{n} (0 ≤ a_{i} ≤ 600) — participants' scores.

It's guaranteed that at least one participant has non-zero score.


-----Output-----

Print a single integer — the desired number of ways.


-----Examples-----
Input
4
1 3 3 2

Output
3

Input
3
1 1 1

Output
1

Input
4
42 0 0 42

Output
1



-----Note-----

There are three ways to choose a subset in sample case one.  Only participants with 3 points will get diplomas.  Participants with 2 or 3 points will get diplomas.  Everyone will get a diploma! 

The only option in sample case two is to award everyone.

Note that in sample case three participants with zero scores cannot get anything.

Difficulty: interview

Starter code:

Solutions:
n=int(input())
s=set()
ar=list(map(int,input().split()))
for x in range(n):
    if(ar[x]!=0):
        s.add(ar[x])
print(len(s))

n = int(input())
a = set(list(map(int, input().split())))
t = 0
if 0 in a:
    t = 1
print(len(a) - t)


n=int(input())
arr=list(map(int,input().strip().split(' ')))
arr=set(arr)
if 0 in arr:
  print(len(arr)-1)
else:
  print(len(arr))

n = int(input())
a = list(set(map(int,input().split())))
a.sort()
if a[0] == 0:
    print(len(a) - 1)
else:
    print(len(a))

n = int(input())
a = [int(v) for v in input().split()]

print(len(set(a) - set([0])))


n=int(input())
a=list(map(int,input().split(' ')))
if 0 in a:
    print(len(set(a))-1)
else:
    print(len(set(a)))

n=input()
a=set(map(int,input().split()))
if 0 in a:
    print(len(a)-1)
else:
    print(len(a))


import atexit
import io
import sys

# Buffering IO
_INPUT_LINES = sys.stdin.read().splitlines()
input = iter(_INPUT_LINES).__next__
_OUTPUT_BUFFER = io.StringIO()
sys.stdout = _OUTPUT_BUFFER

@atexit.register
def write():
    sys.__stdout__.write(_OUTPUT_BUFFER.getvalue())
    

def main():
    n= int(input())
    a = [int(x) for x in input().split()]
    
    dd = set(a)
    print(len(dd) - 1 if 0 in dd else len(dd))

    
def __starting_point():
    main()

__starting_point()

n = input()
l = set([x for x in map(int,input().split()) if x>0])
print(len(l))



n=int(input())
l=[int(i) for i in input().split()]
s=set(l)
k=len(s)
if 0 in s:
	print (k-1)
else:
	print (k)

n = int(input())
a = list(map(int, input().split()))
a = [i for i in a if i > 0]

print(len(set(a)))

n = int(input())
m = {}
line = list(map(int, input().split()))
for i in line:
    if i != 0:
        m[i] = 1
print(len(m))


n = int(input())
s = input().split()
cl = []
for i in range(n):
    if s[i] not in cl and s[i]!='0':
        cl.append(s[i])

print(len(cl))

input()
n = [int(x) for x in input().split()]

n = sorted(set((x for x in n if x > 0)))
print(len(n))

n = int(input())
a = set(list(map(int, input().split())))
if 0 in a:
    print(len(a)-1)
else:
    print(len(a))



n = int(input())
a = set(map(int, input().split()))
print(len(a) - int(0 in a))


import sys

n = int(sys.stdin.readline())
liste = list(map(int, sys.stdin.readline().split()))
nb = 0
tab = [False] * 601
for loop in range(n):
	if not tab[liste[loop]] and liste[loop] != 0:
		nb += 1
		tab[liste[loop]] = True
print(nb)

n = int(input())
a = list(map(int,input().split()))
un = 0
a.sort()
for i in range(n):
    if a[i]>0 and (i==0 or a[i]>a[i-1]):
        un += 1
print(un)



#k=int(input())
#n,m=map(int,input().split())

#a=list(map(int,input().split()))

#b=list(map(int,input().split()))


n=int(input())
a=set(map(int,input().split()))


cnt=0
for i in a:
    if i>0:
        cnt+=1

print(cnt)

from collections import Counter
n = int(input())
a = [int(x) for x in input().split() if x != '0']
print(len(Counter(a)))


n = int(input())
a = sorted(list(map(int, input().split())))
ans = 0
if a[0] != 0:
	ans += 1
for i in range(1, len(a)):
	if a[i] > a[i - 1]:
		ans += 1
print(ans)

from collections import Counter

n = int(input())
a = list(map(int, input().split()))

c = Counter(a)

try:
    del c[0]
except KeyError:
    pass

print(len(c))


good_results = set()
n = int(input())
r = list(map(int, input().split()))
for c in r:
    if c != 0:
        good_results.add(c)
print(len(good_results))


# cook your dish here
n = int(input())
a = list(map(int,input().split()))
a.sort()
count=0
if a[0]!=0:
    count+=1
for i in range(1,n):
    if a[i-1]!=a[i]:
        count+=1
print(count)

n=int(input())
a=list(map(int,input().split()))
a=list(set(sorted(a)))
cnt=0
if a[0]==0: cnt=-1
cnt+=len(list(a))
print(cnt)