const readline = require('readline');

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

const lines = [];
rl.on('line', (line) => {
    lines.push(line);
});

rl.on('close', () => {
    lines.forEach((line) => {
        const nums = line.split(' ');
        const a = Number(nums[0]);
        const b = Number(nums[1]);
        const res = Math.abs(a - b);
        console.log(res);
    });
});