GradeIndex = {}
for i, v in ipairs(Grade) do
  GradeIndex[v] = i-1
end

StageAwardIndex = {}
for i, v in ipairs(StageAward) do
  StageAwardIndex[v] = i-1
end

DifficultyIndex = {}
for i, v in ipairs(Difficulty) do
  DifficultyIndex[v] = i-1
end
