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

#define LINESIZE 100

int main() {
    char vstup[LINESIZE];
    char *brackets = "{[(<";
    char *brackets1 = "}])>";
    char stack[LINESIZE];    
    int position[LINESIZE];    
    int x = 0;                 
    fgets(vstup, LINESIZE, stdin);
    for (int j = 0; j < strlen(vstup); j++) {
        for (int i = 0; i < 4; i++) {
            if (vstup[j] == brackets[i]) {
                stack[x] = brackets[i];  
                position[x] = j;           
                x++;
                break;
            } else if (vstup[j] == brackets1[i]) {
                char expected;
                if (stack[x-1] == '{') expected = '}';
                else if (stack[x-1] == '[') expected = ']';
                else if (stack[x-1] == '(') expected = ')';
                else if (stack[x-1] == '<') expected = '>';

                if (vstup[j] != expected) {
                    printf("Crossed bracket %c in %d, expected %c\n", vstup[j], j, expected);
                    return 0;
                }
                x--;
                break;
            }
        }
    }
    if (x > 0) {
        printf("Unmatched opening bracket %c at position %d\n", stack[x-1], position[x-1]);
    } else {
        printf("All brackets OK\n");
    }

    return 0;
}