Weighing the Grain grain.X Ever the frugal farmer, FR has acquired a balance-beam style scale for weighing the grain he gives the cows. This scale works by reporting if weights placed on its left side match the weight of the grain on its right side. It is not possible to put weights anywhere except the left side. The Ebay auction from which Farmer Ran bought the scale said, "Several weights included". Unfortunately, the weights are not the obvious 1, 2, 4, 8, ... or 1, 1, 1, 1, 5, 10, 10, 10, 10, ... sequences. They are, regrettably, not even 'complete'. That is, the integer sequence of possible weights that _can be constructed_ is missing various integers. Given a set of W (1 <= W <= 1,000) integer weights, calculate the first integer greater than or equal to 1 that can not be represented by some sum of those weights. The answer is guaranteed to fit in 32 signed bits. PROBLEM NAME: grain INPUT FORMAT: * Line 1: A single integer, W * Lines 2..W+1: Each line specifies a weight present in FJ's set of weights. SAMPLE INPUT: 5 1 1 3 4 11 INPUT DETAILS: Five weights of values: 1, 1, 3, 4 and 11 OUTPUT FORMAT: * Line 1: The smallest integer that can not be represented by a sum of the weights SAMPLE OUTPUT: 10 OUTPUT DETAILS: 1-9 are easy to construct; the first four weights sum to 9; there is no way to construct 10