SRC_D = 
SRC_E = 1a_tree.cpp 1b_expr.cpp 1c_trie.cpp 2a_graph.cpp 2b_prog.cpp 2c_span.cpp 3a_tree.cpp 3b_prog.cpp 3c_iter.cpp 4a_graph.cpp 4b_parse.cpp 4c_iter.cpp
# dcacbd1b8232e0ed26cf9c1b1eef7704ec52ad4b  1a_tree.cpp
# 200616dca57c6fc0ef52cb1b73b5b6fdf202f5cc  1b_expr.cpp
# 8cd3432ad891fd52430d083eb70ffa2f5c8344eb  1c_trie.cpp
# f08248a02d6c78d30bd0638afae07541ff7260eb  2a_graph.cpp
# d092be3df728596f32fcfbda916dbe6e572b37d6  2b_prog.cpp
# 79349857f15d9e65772d35cac2082d79c6166e15  2c_span.cpp
# 55089bcf813082b7d44bd37f2d279c79954737fe  3a_tree.cpp
# e0ab181a0543f298965151bfe4b932f4c7f8a7b6  3b_prog.cpp
# 16014b7244aaa63baaf11af2f41db4cb6b7cf37b  3c_iter.cpp
# 8001fd243958af6bff47602c8d86d92acf92ee8e  4a_graph.cpp
# a6fa97833b92bd217dd454010471cfa42db92731  4b_parse.cpp
# f31bd98cc980c689758e96c163c7ae853a7cbf70  4c_iter.cpp