What is the repository number for the solution of method "SCore.Poisson.ngtIndex"?
repository number refers to RepoId; method refers to Name; Name = ‘SCore.Poisson.ngtIndex’
SELECT T1.RepoId FROM Solution AS T1 INNER JOIN Method AS T2 ON T1.Id = T2.SolutionId WHERE T2.Name = 'SCore.Poisson.ngtIndex'