class Solution {
public:
int xorAllNums(vector<int>& nums1, vector<int>& nums2) {
int res = 0;
int n = nums1.size(), m = nums2.size();
if (m % 2 == 1) {
for (int i = 0; i < n; i ++ )
res ^= nums1[i];
}
if (n % 2 == 1){
for (int i = 0; i < m; i ++ )
res ^= nums2[i];
}
return res;
}
};