Buggy python submission (verdict: Time Limit Exceeded):
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    digits = []
    S = 0

    for i in range(M):
        d, c = list(map(int, input().split()))

        if d == 0 and i == 0:
            continue

        for i in range(c):
            digits.append(d)
            S += d

    print((len(digits) - 1) + (S - 1) // 9)


if __name__ == '__main__':
    main()


Fixed submission:
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    N = 0
    S = 0

    for i in range(M):
        d, c = list(map(int, input().split()))

        if d == 0 and i == 0:
            continue

        S += d * c
        N += c

    print((N - 1) + (S - 1) // 9)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    digits = []
    S = 0

    for i in range(M):
        d, c = list(map(int, input().split()))

        if d == 0 and i == 0:
            continue

        for i in range(c):
            digits.append(d)
            S += d

    print((len(d) - 1) + (S - 1) // 9)


if __name__ == '__main__':
    main()


Fixed submission:
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    N = 0
    S = 0

    for i in range(M):
        d, c = list(map(int, input().split()))

        if d == 0 and i == 0:
            continue

        S += d * c
        N += c

    print((N - 1) + (S - 1) // 9)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    # d = [0] * M
    # c = [0] * M
    digits = []
    # d = sorted(d)

    for i in range(M):
        d, c = list(map(int, input().split()))

        if d == 0 and i == 0:
            continue

        for i in range(c):
            digits.append(d)

    if len(digits) == 1:
        print(0)
        return

    if len(digits) == 2:
        if digits[0] == 0:
            print(0)
        else:
            print(1)
        return

    # print(digits)
    ith = 1
    nxt = digits[i] + digits[i+1]
    # print(nxt)
    for i in range(2, len(digits)):
        if nxt + digits[i] >= 10:
            nxt = nxt % 10
            ith += 2
        else:
            nxt = nxt + digits[i]
            ith += 1

    print(ith)


if __name__ == '__main__':
    main()


Fixed submission:
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    N = 0
    S = 0

    for i in range(M):
        d, c = list(map(int, input().split()))

        if d == 0 and i == 0:
            continue

        S += d * c
        N += c

    print((N - 1) + (S - 1) // 9)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    # d = [0] * M
    # c = [0] * M
    digits = []
    # d = sorted(d)

    for i in range(M):
        d, c = list(map(int, input().split()))

        if d == 0 and i == 0:
            continue

        for i in range(c):
            digits.append(d)

    if len(digits) == 1:
        print(0)
        return

    if len(digits) == 2:
        if digits[0] == 1 and digits[1] == 0:
            print(0)
        elif digits[0] == 0:
            print(0)
        else:
            print(1)
        return

    # print(digits)
    ith = 1
    nxt = digits[i] + digits[i+1]
    # print(nxt)
    for i in range(2, len(digits)):
        if nxt + digits[i] >= 10:
            nxt = nxt % 10
            ith += 2
        else:
            nxt = nxt + digits[i]
            ith += 1

    print(ith)


if __name__ == '__main__':
    main()


Fixed submission:
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    N = 0
    S = 0

    for i in range(M):
        d, c = list(map(int, input().split()))

        if d == 0 and i == 0:
            continue

        S += d * c
        N += c

    print((N - 1) + (S - 1) // 9)


if __name__ == '__main__':
    main()

Buggy python submission (verdict: Runtime Error):
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    # d = [0] * M
    # c = [0] * M
    digits = []
    # d = sorted(d)

    for i in range(M):
        d, c = list(map(int, input().split()))
        for i in range(c):
            digits.append(d)

    # print(digits)
    ith = 1
    nxt = digits[i] + digits[i+1]
    # print(nxt)
    for i in range(2, len(digits)):
        if nxt + digits[i] >= 10:
            nxt = nxt % 10
            ith += 2
        else:
            nxt = nxt + digits[i]
            ith += 1

    print(ith)


if __name__ == '__main__':
    main()


Fixed submission:
INF = float("inf")
IINF = 10 ** 18
MOD = 998244353


def main():
    M = int(input())
    N = 0
    S = 0

    for i in range(M):
        d, c = list(map(int, input().split()))

        if d == 0 and i == 0:
            continue

        S += d * c
        N += c

    print((N - 1) + (S - 1) // 9)


if __name__ == '__main__':
    main()