Baekjoon #2504

#include <bits/stdc++.h>

using namespace std;

struct Token {
    int value;
    size_t pos;
};

int main(int argc, char** argv)
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    string input;
    cin >> input;

    vector<Token> tokens;
    tokens.push_back({ 0, '$' });
    for (size_t head = 0; head < input.size(); ++head) {
        if (input[head] == '(' || input[head] == '[') {
            tokens.push_back({ 0, head });
        } else {
            const auto open_tag = (input[head] == ')' ? '(' : '[');
            if (tokens.empty() || input[tokens.back().pos] != open_tag) {
                tokens.clear();
                break;
            }

            Token token = tokens.back();
            tokens.pop_back();

            const auto designated_value = (input[head] == ')' ? 2 : 3);
            if (token.pos + 1 == head) {
                tokens.back().value += designated_value;
            } else {
                tokens.back().value += token.value * designated_value;
            }
        }
    }

    if (tokens.size() != 1) {
        cout << "0\n";
    } else {
        cout << tokens.back().value << '\n';
    }

    return 0;
}

import sys
def input():
    return sys.stdin.readline().rstrip()

s = input()
stack = []

# Check Bracket
for ch in s:
    if ch == '(':
        stack.append('(')
    elif ch == '[':
        stack.append('[')
    elif ch == ')':
        if stack and stack[-1] == '(':
            stack.pop(-1)
        else:
            print(0)
            exit(0)
    else:
        if stack and stack[-1] == '[':
            stack.pop(-1)
        else:
            print(0)
            exit(0)

if stack:
    print(0)
    exit(0)

# [open bracket] + Integer + Integer => [open bracket] + Integer
# compress (add) Integers
def compress():
    # Integer를 하나로 합쳐야 하니깐 길이가 2 이상이어야 함.
    while len(stack) > 1:
        # 두 개의 값이 무조건 Integer이어야 하므로
        # Integer면 첫번째 원소가 None으로 되어 있음
        a, integer1 = stack[-1]
        b, integer2 = stack[-2]
        if a or b:
            break
        stack.pop()
        stack.pop()
        stack.append((None, integer1 + integer2))

for ch in s:
    # open bracket -> append ( open bracket, ~ )
    if ch == '(':
        stack.append(('(', 2))
    elif ch == '[':
        stack.append(('[', 3))
    elif ch == ')' or ch == ']': # Must Be len(stack) ≥ 1
        last1, last2 = stack.pop()
        # Case 1 : ~~ open bracket
        if last1 != None:
            stack.append((None, last2))
        # Case 2 : ~~ open bracket, Integer,
        else:
            a, b = stack.pop()
            stack.append((None, last2 * b))
        compress()

print(stack[-1][1])