Problem: Given three positive integers N, A and B (A < B < N), find the sum of all positive integers less than N, which are divisible by either A or B.

For example, when N = 20, A = 4 and B = 7, the possible values are 4, 7, 8, 12, 14, and 16. Their sum is 61.
Input Format
The only line of the input file contains three space separated integers N, A and B.

Output Format
Output the required sum.

Constraints
10 ≤ N ≤ 50000
2 ≤ A < B < N

SAMPLE INPUT
20 4 7

SAMPLE OUTPUT
61

Solution (in PYTHON):

Solution:
'''
# Read input from stdin and provide input before running code

name = raw_input('What is your name?\n')
print 'Hi, %s.' % name
'''
a,b,c=map(int,raw_input().split())
k=[]
for i in range(0,a):
	if(i%b == 0  or i% c==0):
		k.append(i)
print sum(k)