    function main(input) {
        var data = input.split("\n").map(function(line){return line.split(" ").map(function(value){return parseInt(value)})})
        var k = data[0][1];
        var array = data[1];
        var maxA = max(array);
     
        var maxG = Math.min(maxA + k, sum(array))
        for (var i=maxG; i > 1; i--) {
        	if (isG(i, array, k)) {
        		return console.log(i);
        	}
        }
        return console.log(1);
    }
    function max(array) {
    	return array.reduce(function(a,b){ return Math.max(a, b)})
    }
    function sum(array) {
    	return array.reduce(function(current, value){return current + value}, 0)
    }
    function isG(g, array, k) {
    	var newArray = [];
    	var tempK = 2*k;
    	for (var i=0;i<array.length;i++) {
    		var mod1 = array[i] % g;
    		if (mod1==0) continue;
    		var mod2 = g - mod1;
    		if (k < Math.min(mod1, mod2)) return false;
    		tempK -= Math.min(mod1, mod2);
    		if (tempK < 0) return false;
    		newArray.push([mod1, mod2]);
    	}
    	return traver(newArray, 0, 0, 0, k)
    }
    function traver(array, level, leftCost, rightCost, budget) {
    	if (leftCost > budget) return false;
    	if (rightCost > budget) return false;
    	if (level == array.length) return leftCost == rightCost;
    	if (leftCost < rightCost) {
    		return testLeftPath(array, level, leftCost, rightCost, budget) || testRightPath(array, level, leftCost, rightCost, budget);
    	} else {
    		return testRightPath(array, level, leftCost, rightCost, budget) || testLeftPath(array, level, leftCost, rightCost, budget)
    	}
    	return false;
    }
    function testLeftPath(array, level, leftCost, rightCost, budget) {
    	return traver(array, level + 1, leftCost + array[level][0], rightCost, budget);
    }
    function testRightPath(array, level, leftCost, rightCost, budget) {
    	return traver(array, level + 1, leftCost, rightCost + array[level][1], budget);
    }
    main(require('fs').readFileSync('/dev/stdin', 'utf8'));