if (c >= "a" && c <= "f") {
code += c.charCodeAt(0) - CODE_A + 10
} else if (c >= "0" && c <= "9") {
code += c.charCodeAt(0) - CODE_0
if (c >= "a" && c <= "f") {
code += c.charCodeAt(0) - CODE_A + 10
} else if (c >= "0" && c <= "9") {
code += c.charCodeAt(0) - CODE_0