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:
def main():
    N, A, B = raw_input().split(" ")
    N = int(N)
    A = int(A)
    B = int(B)
    i = A
    ans = 0
    count = 0
    diff = B - A
    while(i < N):
        ans = ans + i
        count = count + 1
        if((i + count * diff) < N and (i + count * diff) % A != 0):
            ans = ans + (i + count * diff)
        i = A * (count + 1)
    print ans
main()