n, x, y = map(int, input().split()) dp = [0] * (n + 1) for c in range(x, n + 1): dp[c] = max(dp[c], dp[c - x] + x) for c in range(y, n + 1): dp[c] = max(dp[c], dp[c - y] + y) print(n - dp[n - 1])