[{"sectionTitle":"Problem Description","type":"Text","text":"**Original source: POI 2001**  \r\n\r\nA positive integer \( n \) greater than or equal to 1 is called an anti-prime if it satisfies the condition that all positive integers less than \( n \) and greater than or equal to 1 have fewer divisors than \( n \). For example: \( 1, 2, 4, 6, 12, 24 \) are all anti-primes.  \r\n\r\nYour task is to compute the largest anti-prime number not exceeding \( n \).","subType":"markdown"},{"sectionTitle":"Input Format","type":"Text","text":"A single line containing a positive integer \( n \).","subType":"markdown"},{"sectionTitle":"Output Format","type":"Text","text":"Output a single integer, which is the largest anti-prime number not exceeding \( n \).","subType":"markdown"},{"sectionTitle":"Sample","type":"Sample","text":"","subType":"markdown","payload":["1000","840"]},{"sectionTitle":"Constraints and Hints","type":"Text","text":"For \( 10\\% \) of the data, \( 1 \\le n \\le 10^3 \);  \r\n\r\nFor \( 40\\% \) of the data, \( 1 \\le n \\le 10^6 \);  \r\n\r\nFor \( 100\\% \) of the data, \( 1 \\le n \\le 2 \\times 10^9 \).","subType":"markdown"}]