The description says “Because of the edge-cases for tiny spirals, the size will be at least 5.”
But Ruby's test go from 0 to 5+
Please change either tests or task description.

@
There is typo in Ruby version.
Starting code is:

# MOD = 998244353 has been predefined

def height(n,m):
  return 0
end

so there is -e:5: syntax error, unexpected ':'

What if all data contain only sex: 'f' and method run with sex: 'm', I think it be wrong.