Okay, here is the exact phrasing:
We want to get two values $A$ and $B$, where we test many values of $A$ to get the smallest value of $B$. $B$ is the coefficient of $x^{15}$ in the result of: $(1 + x)^A \pmod{p, x^{38} - 5}$. $p = 2975390752039679348694694675193$, a prime number. $x^{38} - 5$ is an irreducible polynomial in the field $F_p[x]$.
The range of allowable values of $A$ and $B$ are: $1 \le A \le p^{38} - 1$ and $0 <= B < p$