input()
l=input().split()
_new=0
l.sort()
if l[0] != l[1]:
    _new=_new+1
for i in range(1,len(l)-1):
    if (l[i]!=l[i-1]) and (l[i] != l[i+1]):
        _new=_new+1
if l[-1] != l[-2]:
    _new=_new+1
    
print(_new)