solution.js

'use strict';

const readline = require('readline');

let inputString = []
let currentLine = 0;
let max         = 0;
let i           = 0;

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

rl.on('line', (el) => {
    if(max == 0){
        max = parseInt(el) + 1;
    }

    i++;

    inputString.push(el.replace(/\s\s+/g, ' '));

    if(i==max){
        rl.close();
    }
});


rl.on('close', () => {
    main();
});

function readLine() {
    return inputString[currentLine++];
}

/*
 * Return a count of the total number of objects 'o' satisfying o.x == o.y.
 * 
 * Parameter(s):
 * objects: an array of objects with integer properties 'x' and 'y'
 */
function getCount(objects) {
    return objects.filter(({x, y}) => x == y).length;
}


function main() {
    const n = +(readLine());
    let objects = [];
    
    for (let i = 0; i < n; i++) {
        const [a, b] = readLine().split(' ');
        
        objects.push({x: +(a), y: +(b)});
    }
    
    console.log(getCount(objects));
}