#include <stdio.h>
#include <string.h>
#include <stdbool.h>

bool brackets(const char *code) {
    int stack[100];
    int top = -1;

    for (int i = 0; code[i] != '\0'; i++) {
        if (code[i] == '(' || code[i] == '[' || code[i] == '{' || code[i] == '<') {
            stack[++top] = i;
        } else if (code[i] == ')' || code[i] == ']' || code[i] == '}' || code[i] == '>') {
            if (top == -1) {
                printf("Unexpected closing bracket %c in %d \n", code[i], i);
                return false;
            }

            int opening = stack[top--];
            char expected_opening = 0;

            if (code[i] == ')') {
                expected_opening = '(';
            } else if (code[i] == ']') {
                expected_opening = '[';
            } else if (code[i] == '}') {
                expected_opening = '{';
            } else if (code[i] == '>') {
                expected_opening = '<';
            }

            if (code[opening] != expected_opening) {
                printf("Crossed bracket %c in %d, expected %c \n", code[i], i, expected_opening);
                return false;
            }
        }
    }

    if (top != -1) {
        int opening = stack[top];
        printf("Unclosed bracket %c in %d\n", code[opening], opening);
        return false;
    }

    return true;
}

int main() {
    char code[100];
    fgets(code, sizeof(code), stdin);
 
    if (code[strlen(code) - 1] == '\n') {
        code[strlen(code) - 1] = '\0';
    }

    printf("Read: %s\n", code);

    if (brackets(code)) {
        printf("All brackets OK\n");
    }

    return 0;
}