#include <cstdio>
#include <cstring>

using namespace std;

const int N = 50 + 5;

int a[N][N];
char r[N], c[N];
bool rr[N], cc[N];

int main() {
    scanf("%s%s", r, c);
    int nr = strlen(r);
    int nc = strlen(c);
    for (int i = 0; i < nr; i++) {
        rr[i] = r[i] - '0' != nc % 2;
    }
    for (int i = 0; i < nc; i++) {
        cc[i] = c[i] - '0' != nr % 2;
    }
    for (int i = 0; i < nr; i++) {
        for (int j = 0; j < nc; j++) {
            a[i][j] = 1;
        }
    }
    for (int i = 0; i < nr; i++) {
        if (rr[i]) {
            //printf("need fix -- %d\n", i);
            bool flag = false;
            for (int j = 0; j < nc; j++) {
                if (cc[j]) {
                    rr[i] = false;
                    cc[j] = false;
                    a[i][j] ^= 1;
                    flag = true;
                    break;
                }
            }
            if (!flag) {
                //puts("oops");
                rr[i] = false;
                cc[0] = true;
                a[i][0] ^= 1;
            }
        }
    }
    /*
    puts("---");
    for (int i = 0; i < nr; i++) {
        for (int j = 0; j < nc; j++) {
            printf("%d", a[i][j]);
        }
        puts("");
    }
    puts("---");
    */
    for (int i = 0; i < nc; i++) {
        if (cc[i]) {
            bool flag = false;
            for (int j = 0; j < nr; j++) {
                if (rr[j]) {
                    cc[i] = false;
                    rr[j] = false;
                    a[j][i] ^= 1;
                    flag = true;
                    break;
                }
            }
            if (!flag) {
                cc[i] = false;
                rr[0] = true;
                a[0][i] ^= 1;
            }
        }
    }
    for (int i = 0; i < nr; i++) {
        if (rr[i]) {
            puts("-1");
            return 0;
        }
    }
    for (int i = 0; i < nc; i++) {
        if (cc[i]) {
            puts("-1");
            return 0;
        }
    }
    for (int i = 0; i < nr; i++) {
        int cnt = 0;
        for (int j = 0; j < nc; j++) {
            cnt += a[i][j];
        }
    }
    for (int i = 0; i < nr; i++) {
        for (int j = 0; j < nc; j++) {
            printf("%d", a[i][j]);
        }
        puts("");
    }
    return 0;
}