itemcode = {
    # identifiers and constants
    "id": 10,
    "const": 11,

    # reserved keywords
    "with": 100,
    "as": 101,
    "int": 102,
    "float": 103,
    "string": 104,
    "if": 105,
    "else": 106,
    "while": 107,
    "read": 108,
    "write": 109,

    # operators
    "=": 200,
    "==": 201,
    "!=": 202,
    "<": 203,
    ">": 204,
    "<=": 205,
    ">=": 206,
    "+": 207,
    "-": 208,
    "*": 209,
    "/": 210,
    "%": 211,
    "**": 212,

    # separators
    ":": 300,
    ",": 301,
    "&": 302
}