eBGDAElet ring1=722000300200030044let ring24x200030033202000let ring34x0220000032002000let ring40220000035003040let ringlet ring50(2)(2)(0)0000(3)(2)(2)(0)356235let ring700000(3)(2)(2)(0)38=929101112131415161718192021222324252627282930314x1,2,33243334353637383940414243444546474849505152535455565758596061626364656667686970717273747576