トヨタ自動車プログラミングコンテスト2023#3(AtCoder Beginner Contest 306)

import sys


def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    n = int(input().rstrip('\n'))
    s = str(input().rstrip('\n'))
    print("".join([v * 2 for v in s]))


if __name__ == '__main__':
    solve()

import sys


def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    ans = 0
    a = list(map(int, input().rstrip('\n').split()))
    for i in range(len(a)):
        ans += pow(2, i) * a[i]
    print(ans)


if __name__ == '__main__':
    solve()

import sys
import collections


def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    n = int(input().rstrip('\n'))
    a = list(map(int, input().rstrip('\n').split()))
    ls = []
    d = collections.defaultdict(int)
    for i in range(3 * n):
        if a[i] not in d:
            d[a[i]] += 1
        elif d[a[i]] == 1:
            ls.append([i, a[i]])
            d[a[i]] += 1
    ls.sort()
    print(*[ls[i][1] for i in range(n)])


if __name__ == '__main__':
    solve()

import sys


def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    n = int(input().rstrip('\n'))
    dp = [[-pow(10, 30)] * 2 for _ in range(n)]
    for i in range(n):
        x, y = list(map(int, input().rstrip('\n').split()))
        if i == 0:
            if x == 0:
                dp[i][0] = max(0, y)
                dp[i][1] = 0
            else:
                dp[i][1] = max(0, y)
                dp[i][0] = 0
        else:
            if x == 0:
                dp[i][0] = max(dp[i-1][0], dp[i-1][0] + y, dp[i-1][1] + y)
                dp[i][1] = dp[i-1][1]
            else:
                dp[i][1] = max(dp[i-1][1], dp[i-1][0] + y)
                dp[i][0] = dp[i-1][0]
    print(max(dp[-1]))


if __name__ == '__main__':
    solve()