We‘ll call an array of n non-negative integers a[1], a[2], ..., a[n] interesting, if it meets m constraints. The i-th of the m constraints consists of three integers li, ri, qi (1 ≤ li ≤ ri ≤ n) meaning that value 
should be equal to qi.
Your task is to find any interesting array of n elements or state that such array doesn‘t exist.
Expression x&y means the bitwise AND of numbers x and y. In programming languages C++, Java and Python this operation is represented as "&", in Pascal — as "and".
Input
The first line contains two integers n, m (1 ≤ n ≤ 105, 1 ≤ m ≤ 105) — the number of elements in the array and the number of limits.
Each of the next m lines contains three integers li, ri, qi (1 ≤ li ≤ ri ≤ n, 0 ≤ qi < 230) describing the i-th limit.
Output
If the interesting array exists, in the first line print "YES" (without the quotes) and in the second line print n integers a[1], a[2], ..., a[n](0 ≤ a[i] < 230) decribing the interesting array. If there are multiple answers, print any of them.
If the interesting array doesn‘t exist, print "NO" (without the quotes) in the single line.
题意为，有一个数组，告诉你一些区间的 & 值，问你是否存在这样的数组，存在输出一组
解法CF上面有题解，我就不说咯
总结一下这个题学到的东西：
1，本来以为区间更改用线段树实现会很快，这次知道如果不是边改便询问的话，有一个更好的方法。
2，原来&也是满足线段树处理的，以前一直不敢用，这次涨见识了