B"A frog is initially at position 0 on the number line. The frog has two positive integers a and b . From a position k , it can either jump to position k+a or k-b . Let f(x) be the number of distinct integers the frog can reach if it never jumps on an integer outside the interval [0, x] . The frog doesn't need to visit all these integers in one trip, that is, an integer is counted if the frog can somehow reach it if it starts from 0 . Given an integer m , find sum_{i=0}^{m} f(i) . That is, find the sum of all f(i) for i from 0 to m . The first line contains three integers m, a, b ( 1 <= q m <= q 10^9, 1 <= q a,b <= q 10^5 ). Print a single integer, the desired sum. In the first example, we must find f(0)+f(1)+ ldots+f(7) . We have f(0) = 1, f(1) = 1, f(2) = 1, f(3) = 1, f(4) = 1, f(5) = 3, f(6) = 3, f(7) = 8 . The sum of these values is 19 . In the second example, we have f(i) = i+1 , so we want to find sum_{i=0}^{10^9} i+1 . In the third example, the frog can't make any jumps in any case. "...