CF1607B.Odd Grasshopper

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题目描述

The grasshopper is located on the numeric axis at the point with coordinate x0x_0 .

Having nothing else to do he starts jumping between integer points on the axis. Making a jump from a point with coordinate xx with a distance dd to the left moves the grasshopper to a point with a coordinate xdx - d , while jumping to the right moves him to a point with a coordinate x+dx + d .

The grasshopper is very fond of positive integers, so for each integer ii starting with 11 the following holds: exactly ii minutes after the start he makes a jump with a distance of exactly ii . So, in the first minutes he jumps by 11 , then by 22 , and so on.

The direction of a jump is determined as follows: if the point where the grasshopper was before the jump has an even coordinate, the grasshopper jumps to the left, otherwise he jumps to the right.

For example, if after 1818 consecutive jumps he arrives at the point with a coordinate 77 , he will jump by a distance of 1919 to the right, since 77 is an odd number, and will end up at a point 7+19=267 + 19 = 26 . Since 2626 is an even number, the next jump the grasshopper will make to the left by a distance of 2020 , and it will move him to the point 2620=626 - 20 = 6 .

Find exactly which point the grasshopper will be at after exactly nn jumps.

输入格式

The first line of input contains an integer tt ( 1t1041 \leq t \leq 10^4 ) — the number of test cases.

Each of the following tt lines contains two integers x0x_0 ( 1014x01014-10^{14} \leq x_0 \leq 10^{14} ) and nn ( 0n10140 \leq n \leq 10^{14} ) — the coordinate of the grasshopper's initial position and the number of jumps.

输出格式

Print exactly tt lines. On the ii -th line print one integer — the answer to the ii -th test case — the coordinate of the point the grasshopper will be at after making nn jumps from the point x0x_0 .

输入输出样例

  • 输入#1

    9
    0 1
    0 2
    10 10
    10 99
    177 13
    10000000000 987654321
    -433494437 87178291199
    1 0
    -1 1

    输出#1

    -1
    1
    11
    110
    190
    9012345679
    -87611785637
    1
    0

说明/提示

The first two test cases in the example correspond to the first two jumps from the point x0=0x_0 = 0 .

Since 00 is an even number, the first jump of length 11 is made to the left, and the grasshopper ends up at the point 01=10 - 1 = -1 .

Then, since 1-1 is an odd number, a jump of length 22 is made to the right, bringing the grasshopper to the point with coordinate 1+2=1-1 + 2 = 1 .

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