import * as readline from 'readline';

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

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

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