[{"sectionTitle":"题目描述","type":"Text","text":"给出两个正整数 $A,B$，求它们的最大公约数。","subType":"markdown"},{"sectionTitle":"输入格式","type":"Text","text":"输入共两行，第一行一个正整数 $A$，第二行一个正整数 $B$。","subType":"markdown"},{"sectionTitle":"输出格式","type":"Text","text":"在第一行输出一个整数，表示 $A,B$ 的最大公约数。","subType":"markdown"},{"sectionTitle":"样例","type":"Sample","text":"","subType":"markdown","payload":["18\n24","6"]},{"sectionTitle":"数据范围与提示","type":"Text","text":"对于 $60\\%$ 的数据，$1\\le A,B\\le 10^{18}$； \r\n对于 $100\\%$ 的数据，$1\\le A,B\\le 10^{3000}$。","subType":"markdown"}]