my @a = ([  1,  8],
         [  9, 11],
         [ 20,  2],
         [ 22,  9],
         [ 31,  7],
         [ 38,  8],
         [ 46,  8],
         [ 54,  8],
         [ 62, 30],
         [ 92, 12],
         [104, 30]);