CF793F.Julia the snail

普及/提高-

通过率:0%

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题目描述

After hard work Igor decided to have some rest.

He decided to have a snail. He bought an aquarium with a slippery tree trunk in the center, and put a snail named Julia into the aquarium.

Igor noticed that sometimes Julia wants to climb onto the trunk, but can't do it because the trunk is too slippery. To help the snail Igor put some ropes on the tree, fixing the lower end of the ii -th rope on the trunk on the height lil_{i} above the ground, and the higher end on the height rir_{i} above the ground.

For some reason no two ropes share the same position of the higher end, i.e. all rir_{i} are distinct. Now Julia can move down at any place of the trunk, and also move up from the lower end of some rope to its higher end. Igor is proud of his work, and sometimes think about possible movements of the snail. Namely, he is interested in the following questions: «Suppose the snail is on the trunk at height xx now. What is the highest position on the trunk the snail can get on if it would never be lower than xx or higher than yy ?» Please note that Julia can't move from a rope to the trunk before it reaches the higher end of the rope, and Igor is interested in the highest position on the tree trunk.

Igor is interested in many questions, and not always can answer them. Help him, write a program that answers these questions.

输入格式

The first line contains single integer nn ( 1<=n<=1000001<=n<=100000 ) — the height of the trunk.

The second line contains single integer mm ( 1<=m<=1000001<=m<=100000 ) — the number of ropes.

The next mm lines contain information about the ropes.

The ii -th of these lines contains two integers lil_{i} and rir_{i} ( 1<=li<=ri<=n1<=l_{i}<=r_{i}<=n ) — the heights on which the lower and the higher ends of the ii -th rope are fixed, respectively. It is guaranteed that all rir_{i} are distinct.

The next line contains single integer qq ( 1<=q<=1000001<=q<=100000 ) — the number of questions.

The next qq lines contain information about the questions.

Each of these lines contain two integers xx and yy ( 1<=x<=y<=n1<=x<=y<=n ), where xx is the height where Julia starts (and the height Julia can't get lower than), and yy is the height Julia can't get higher than.

输出格式

For each question print the maximum reachable for Julia height.

输入输出样例

  • 输入#1

    8
    4
    1 2
    3 4
    2 5
    6 7
    5
    1 2
    1 4
    1 6
    2 7
    6 8
    

    输出#1

    2
    2
    5
    5
    7
    
  • 输入#2

    10
    10
    3 7
    1 4
    1 6
    5 5
    1 1
    3 9
    7 8
    1 2
    3 3
    7 10
    10
    2 4
    1 7
    3 4
    3 5
    2 8
    2 5
    5 5
    3 5
    7 7
    3 10
    

    输出#2

    2
    7
    3
    3
    2
    2
    5
    3
    7
    10
    

说明/提示

The picture of the first sample is on the left, the picture of the second sample is on the right. Ropes' colors are just for clarity, they don't mean anything.

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