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

#define MAX_STACK 1024
typedef struct
{
    char data[MAX_STACK];
    int sp;
} stack;

static char *ReadLine(char *p, size_t size, FILE *fp)
{
    if ((p=fgets(p, size, fp)))
    {
        size_t l = strlen(p);

        while(l && p[l-1] == '\n')
        {
            p[--l] = 0;
        }
    }

    return p;
}

static char AnyOpen(int c)
{
    switch(c)
    {
        case '(':
            return 1;
        case '[':
            return 1;
        case '{':
            return 1;
        case '<':
            return 1;
        default:
            return 0;
    }
}

static char AnyClose(int c)
{
    switch(c)
    {
        case ')':
            return 1;
        case ']':
            return 1;
        case '}':
            return 1;
        case '>':
            return 1;
        default:
            return 0;
    }
}

static char Close(int fromopen)
{
    switch(fromopen)
    {
        case '(':
            return ')';
        case '[':
            return ']';
        case '{':
            return '}';
        case '<':
            return '>';
        default:
            return 0;
    }
}

static void Push(stack *s, char c)
{
    if (s->sp == MAX_STACK)
    {
        printf("Stack too big!\n");
        exit(1);
    }

    s->data[s->sp++] = c;
}


static char Pop(stack *s)
{
    if (s->sp == 0)
    {
        printf("Stack too small!\n");
        exit(1);
    }

    return s->data[--s->sp];
}


static long CompleteLine(char *p)
{
    char c = 0;
    long score = 0;
    stack s = {0};

    while((c = *p++))
    {
        if (AnyOpen(c))
        {
            Push(&s, c);
        }

        if (AnyClose(c))
        {
            char close = Close(Pop(&s));

            if (close != c)
            {
                return 0;
            }
        }
    }

    while(s.sp)
    {
        char close = Close(Pop(&s));

        score *= 5;
        switch(close)
        {
            case ')':
                score += 1;
                break;
            case ']':
                score += 2;
                break;
            case '}':
                score += 3;
                break;
            case '>':
                score += 4;
                break;
        }
    }

    return score;
}


static int Compare(const void *a, const void *b)
{
    const long *pa = a;
    const long *pb = b;

    if (*pa == *pb)
    {
        return 0;
    }
    else if (*pa < *pb)
    {
        return -1;
    }
    else
    {
        return 1;
    }
}


int main(void)
{
    char buff[0x8000];
    long score[1204] = {0};
    int num_score = 0;
    long f = 0;

    while(ReadLine(buff, sizeof buff, stdin))
    {
        f = CompleteLine(buff);

        if (f)
        {
            score[num_score++] = f;
        }
    }

    qsort(score, num_score, sizeof score[0], Compare);

    printf("middle = %ld\n", score[num_score / 2]);

    return 0;
}