#!/usr/bin/env node

const list1=[];
const list2=[];

require('fs').readFileSync('input.txt','utf8').split('\n').filter(i=>i).forEach(line=>{
 const parts = line.split('   ').map(i=>parseInt(i));
 list1.push(parts[0]);
 list2.push(parts[1]);
});

const counts = require('lodash').countBy(list2);

var absurdscore=0;
for(let num of list1) {
 absurdscore+=num*(counts[num]||0);
}

console.log('Result:',absurdscore);