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

#define MAX_WIDTH 32

int main(void) {
    /* Key takeaway: if think of the input as a matrix, we can
     * sum the columns and count the number of entries and know
     * that if N entries had X sum, there's X 1's and N-X 0's.
     */
    int counts[MAX_WIDTH] = { 0 };
    int c;
    int col = 0;
    int n = 0;
    while ((c = getchar()) != EOF) {
        switch (c) {
            case '0':
                col++;
                break;
            case '1':
                counts[col]++;
                col++;
                break;
            case '\n':
                /* reset the column */
                col = 0;
                n++;
                break;
            default:
                fprintf(stderr, "bad input");
                exit(1);
                break;
        }
    }

    /* convert counts into a bitmask of 1/0 based on which was max */
    unsigned int gamma = 0;
    unsigned int eps = 0;
    for (int i = 0; i < MAX_WIDTH; i++) {
        if (counts[i] == 0) {
            /* assume we see each at least once, so this was the end of width */
            break;
        }
        /* boost the last value to make room for more! */
        gamma <<= 1;
        eps <<= 1;
        if (counts[i] > n / 2) {
            gamma |= 1;
        } else {
            eps |= 1;
        }
    }
    printf("%u\n", eps * gamma);
    return 0;
}