int rgrep_matches(char *line, char *pattern) {

	int i = 0;
	while (line[i] != 0)
	{
		if ((line[i] == pattern[i] || pattern[i] == '.' ) && pattern[i] != '+' && pattern[i] != '?' && pattern[i] != '\\')
		{
			char a[MAXSIZE], b[MAXSIZE];
			int k = 0, m = 0, n = 0;
			while (pattern[k] != 0)
			{
				a[k] == pattern[k+1];
				if (a[k] > 0)
					k++;
			}
			while (line[m] != 0)
			{
				b[m] == line[m+1];
				if (b[m] > 0)
					m++;
			}
			n = rgrep_matches(a, b);
			if (n == 0)
				return 0;

		}

		else if (pattern[i+1] == '+' && pattern[i] != '\\')
		{
			int k = 0, l = 0, n = 0;
			while (line[i] != 0)
			{
				char b[MAXSIZE];
				for (k = 0; k < i; k++)
					b[k] = pattern[0];
				while (pattern[l] != 0)
				{
					if (pattern[l] == '+')
					{
						l++;
						continue;
					}
					b[k] = pattern[l];
					k++;
					l++;

				}
				n = rgrep_matches(line, b);
				if (n == 0)
					return 0;
			}

		}
		else if (pattern[i+1] == '?' && pattern[i] != '\\' && pattern[i] != '+' && pattern[i] != 0)
		{
			char a[MAXSIZE], b[MAXSIZE];
			int j = 0, match = -1, match1 = -1;
			if (match != 0)
			{
				while (pattern[j+1] != 0)
				{
					a[j] = pattern[j+1];
					j++;
				}
				match = rgrep_matches(line, a);
			}
			if (match1 != 0)
			{
				while (pattern[j+2] != 0)
				{
					b[j] = pattern[j+2];
					j++;
				}
				match1 = rgrep_matches(line, b);
			}
			if (match == 0 && match1 == 0)
				return 0;

		}
		else if (pattern[i] == '\\')
		{
			char a[MAXSIZE], b[MAXSIZE];
			int j = 0, k = 0, n = 0;
			if (line[i] == pattern[i+1])
			{
				while (line[j] != 0)
				{
					a[j] = line[j+1];
					j++;
				}
				while (pattern[k+2] != 0)
				{
					b[k] = pattern[k+2];
					k++;
				}
			}
			n = rgrep_matches(a, b);
			if ( n == 0)
				return 0;
		}

	}



    return 1;
}

int main(int argc, char **argv) {
    if (argc != 2) {
        fprintf(stderr, "Usage: %s <PATTERN>\n", argv[0]);
        return 2;
    }

    /* we're not going to worry about long lines */
    char buf[MAXSIZE];

    while (!feof(stdin) && !ferror(stdin)) {
        if (!fgets(buf, sizeof(buf), stdin)) {
            break;
        }
        if (rgrep_matches(buf, argv[1])) {
            fputs(buf, stdout);
            fflush(stdout);
        }
    }

    if (ferror(stdin)) {
        perror(argv[0]);
        return 1;
    }

    return 0;
}