Python3中字典insideanotherdictionary的空间复杂度

Question

词典内部词典的空间复杂度是多少。我想抽象的想法是：

D = { KEY0: { key0_0: "val0_0", key0_1: "val0_1", ... , key0_n0: "val0_n0" } ,
      KEY1: {key1_0: "val1_0", ... , key1_n1: "val1_n1" } ,
      ... ,
      KEYm: { keym_0: "valm_0", ... , keym_nm: "valm_nm" }
      }

所以我想是O(M*N)，我猜是O(min(N,M)*min(N,M))，所以O(N^2)