CodeForces 664A Complicated GCD

 
A. Complicated GCD
time limit per test:1 second
memory limit per test256 megabytes:
input:standard input
output:standard output

Greatest common divisor GCD(a, b) of two positive integers a and b is equal to the biggest integer d such that both integers a and b are divisible by d. There are many efficient algorithms to find greatest common divisor GCD(a, b), for example, Euclid algorithm.

Formally, find the biggest integer d, such that all integers a, a + 1, a + 2, ..., b are divisible by d. To make the problem even more complicated we allow a and b to be up to googol, 10100 — such number do not fit even in 64-bit integer type!

Input

The only line of the input contains two integers a and b (1 ≤ a ≤ b ≤ 10100).

Output

Output one integer — greatest common divisor of all integers from a to b inclusive.

Examples
Input
1 2
Output
1
Input
61803398874989484820458683436563811772030917980576 61803398874989484820458683436563811772030917980576
Output
61803398874989484820458683436563811772030917980576


在数论中,如果两个或两个以上的整数的最大公约数是1,则称它们为互质。
性质:相邻两个自然数互质。即,GCD(a,a+1)=1,用辗转相除法可以算出。也可以用定理证明,定理:如果存在整数x1, ... ,xk,使得 a1x1 + ... + akxk = 1,则 a1,...,ak 是即约的。
因此只需要判读输入的两个数是否相,若相等输出这个数,否则输出1。

原文地址:https://www.cnblogs.com/cumulonimbus/p/5777906.html