Coefficient of a Specific Term in a Polynomial Expansion

Given a polynomial expansion

$$ (x^2+x+1)^n $$

find the coefficient of the term $$x^i$$ in its expanded form.

inputFormat

The input consists of two integers n and i separated by a space, where n is the exponent in the expansion and i is the exponent of x whose coefficient is to be computed.

outputFormat

Output a single integer representing the coefficient of the term $$x^i$$ in the expanded polynomial $$ (x^2+x+1)^n $$.

sample

1 0

1