Let's consider equation:
x2+s(x) \cdot x-n=0,
where x,n are positive integers, s(x) is the function, equal to the sum of digits of number x in the decimal number system.

You are given an integer n, find the smallest positive integer root of equation x, or else determine that there are no such roots.

A single line contains integer n (1 \le n \le 1018) - the equation parameter.

Please, do not use the %lld specifier to read or write 64-bit integers in C++. It is preferred to use cin, cout streams or the %I64d specifier.

Print -1, if the equation doesn't have integer positive roots. Otherwise print such smallest integer x (x \gt 0), that the equation given in the statement holds.

In the first test case x=1 is the minimum root. As s(1)=1 and 12+1 \cdot 1-2=0.

In the second test case x=10 is the minimum root. As s(10)=1+0=1 and 102+1 \cdot 10-110=0.

In the third test case the equation has no roots.