题解 | 变幻莫测

const rl = require("readline").createInterface({ input: process.stdin });
var iter = rl[Symbol.asyncIterator]();
const readline = async () => (await iter.next()).value;

void (async function () {
    // 有点取巧了
    while ((line = await readline())) {
        let tokens = line.split(" ");
        const a = +tokens[0];
        const b = +tokens[1];
        if (a === b) {
            console.log(0);
        } else if (b === 0) {
            console.log(1);
        } else if (a === 0) {
            console.log(2);
        } else if (a + b === 0) {
            console.log(3);
        } else {
            console.log(-1);
        }
    }
})();