'use strict'

const main = input => {
	const s = input.trim()
	let t1 = ''

	for (let i = 0; i < s.length; i++) {
		if (i % 2 === 0) t1 += s[i]
	}

	console.log(t1)
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'))
