#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>using namespace std;#define maxn 50000int ak[maxn], bk[maxn], b[maxn], k[maxn];char st[maxn];int n;int value(char ch){ return ch >= '0' && ch <= '9' ? ch - '0' : ch - 'A' + 10;}void make(char *st, int f[]){ int len = strlen(st); for (int i = 0; i < len; i++) { if (i & 1) f[i >> 1] += value(st[i]); else f[i >> 1] = value(st[i]) << 4; }}int main(){ scanf("%s", st); n = strlen(st) / 2; make(st, ak); scanf("%s", st); make(st, bk); b[0] = 32; for (int i = 0; i < n; i++) { k[i] = b[i] ^ bk[i]; b[i + 1] = k[i] ^ ak[i]; } k[n] = b[n] ^ bk[n]; for (int i = 0; i < n + 1; i++) printf("%02X", k[i]); putchar('n'); return 0;}
