x = readInt()
#PREMISES FOR ATTACHED PROOF, IF ANY: 
# True
#PREMISES FOR NEXT LINE: 
n = readInt()
#PREMISES FOR ATTACHED PROOF, IF ANY: 
# True
#PREMISES FOR NEXT LINE: 
i = 0
#PREMISES FOR ATTACHED PROOF, IF ANY: 
# (i == 0)
#PREMISES FOR NEXT LINE: 
# (i == 0)
sum = 0
#PREMISES FOR ATTACHED PROOF, IF ANY: 
# (sum == 0)
# (i == 0)
#PREMISES FOR NEXT LINE: 
# (sum == 0)
# (i == 0)

while i != n :
    """{ invariant sum == x* i 
         modifies i, sum         }"""
    #PREMISES FOR LOOP BODY: 
    # (i != n)
    # (sum == (x * i))
    sum = sum + x
    #PREMISES FOR ATTACHED PROOF, IF ANY: 
    # (sum == (sum_old + x))
    # (i != n)
    # (sum_old == (x * i))
    """{ 1.OK  sum == sum_old + x     premise
         2.OK  sum_old  == x * i     premise
         3.OK  sum == (x*i) + x      algebra 2 1
    }"""
    #PREMISES FOR NEXT LINE: 
    # (sum == ((x * i) + x))
    i = i + 1
    #PREMISES FOR ATTACHED PROOF, IF ANY: 
    # (i == (i_old + 1))
    # (sum == ((x * i_old) + x))
    """{ 1.OK i == i_old + 1  premise
         2.OK sum == (x * i_old) + x   premise
         3.OK i_old == i - 1         algebra 1
         4.OK sum == (x * (i - 1)) + x   subst 3 2
         5.OK sum == x * i            algebra  4
    }"""
    #PREMISES FOR NEXT LINE: 
    # (sum == (x * i))
#PREMISES FOR NEXT LINE: 
# (sum == (x * i))
# not (i != n)

"""{ 1.OK sum == x * i   premise
     2.OK  not(i != n)   premise
     3.OK  i == n        algebra 2
     4.OK  sum == x * n  subst 3 1
}"""
#PREMISES FOR NEXT LINE: 
# (sum == (x * n))