def succ(x) :
    """{ pre x > 0  
         post y > x  and  y > 0
         return y
    }"""
    #PREMISES FOR NEXT LINE: 
    # (x > 0)
    y = x + 1
    #PREMISES FOR ATTACHED PROOF, IF ANY: 
    # (y == (x + 1))
    # (x > 0)
    #PREMISES FOR NEXT LINE: 
    # (y == (x + 1))
    # (x > 0)
    return y
    #PREMISES FOR NEXT LINE: 
    # ((y > x) and (y > 0))
#PREMISES FOR NEXT LINE: 


a = readInt()
#PREMISES FOR ATTACHED PROOF, IF ANY: 
# True
#PREMISES FOR NEXT LINE: 
assert a > 1
#PREMISES FOR NEXT LINE: 
# (a > 1)
"""{ 1.OK a > 1   premise
     2.OK a > 0   algebra 1
}"""
#PREMISES FOR NEXT LINE: 
# (a > 0)
# (a > 1)
b = succ(a)
#PREMISES FOR ATTACHED PROOF, IF ANY: 
# ((b > a) and (b > 0))
# (a > 0)
# (a > 1)
"""{ 1.OK  b > a  and  b > 0   premise   # from  post_succ
     2.OK  b > a               ande 1
}"""
#PREMISES FOR NEXT LINE: 
# (b > a)
# ((b > a) and (b > 0))
# (a > 0)
# (a > 1)