1165C - Good String - CodeForces Solution

import sys,os
from collections import defaultdict,Counter
from math import ceil,gcd,sqrt
from bisect import bisect_left

f=False
INT_MAX=sys.maxsize
if os.getcwd()=="/Users/mehtaparityatinbhai/Desktop/test_codes":
	sys.stdin = open('inp.txt', 'r')
	sys.stdout = open('out.txt', 'w')
	f=True

def lcm(a,b):
	return (a*b)//gcd(a,b)

def readint():
	return int(input())

def readlst():
	return list(map(int, input().split()))


def leftrotate(a,l,r):
	return a[l+1:r]+a[:l+1]+a[r:]


def is_prime(n):
    if n < 5 or n & 1 == 0 or n % 3 == 0:
        return 2 <= n <= 3
    s = ((n - 1) & (1 - n)).bit_length() - 1
    d = n >> s
    for a in [2, 325, 9375, 28178, 450775, 9780504, 1795265022]:
        p = pow(a, d, n)
        if p == 1 or p == n - 1 or a % n == 0:
            continue
        for _ in range(s):
            p = (p * p) % n
            if p == n - 1:
                break
        else:
            return False
    return True





def sol(cnt):
	n=readint()
	s=input()
	res=''
	for i in range(n):
		if len(res)&1==0:
			res+=s[i]
		else:
			if res[-1]==s[i]:
				continue
			else:
				res=res+s[i]
	if len(res)&1:
		res=res[:-1]
	print(len(s)-len(res))
	print(res)
	return

def main():
	tc=1
		cnt=0
	for _ in range(tc):
		cnt+=1
		sol(cnt)
main()