Description

You are tasked to determine the kth term of the binomial expansion of the expression $(x + y)^n$.

Input Format

The input starts with an integer M > 0, followed by M pairs of integers k, n, where $1 \le k \le n+1$ and $0 \lt n \lt 1000$.

Output Format

For every pair of integers k, n, output the correct kth term of the binomial expansion of $(x+y)^n$. If the coefficient is 1, the coefficient should not be printed. If the power of x is 0, the variable x should not be printed. If the power of y is 0, the variable y should not be printed. If the power of x is 1, the power of variable x should not be printed. If the power of y is 1, the power of variable y should not be printed. In general, the format of each output is $c x^a y^b$, where c is the coefficient, a is the power of x and b is the power of y.