process.stdin.resume();
process.stdin.setEncoding("ascii");
let input = [];
let output = "";
process.stdin.on("data", function (chunk) {
    input.push(...chunk.trim());
});
process.stdin.on("end", function () {
    const firstLine = input.slice(0, input.indexOf('\n'));
    const secondLine = input.slice(input.indexOf('\n') + 1);

    for (let i = 0; i < firstLine.length; i++) {
        output += (firstLine[i] === secondLine[i] ? '0' : '1');
    }
    console.log(output);
});