View Compilation Error

0_0_36287684_9072.cpp: In function 'int main()':
0_0_36287684_9072.cpp:22:14: error: 'a' was not declared in this scope
     int w = (a[i] >> j) & 1;
              ^
0_0_36287684_9072.cpp:33:14: error: 'a' was not declared in this scope
     int w = (a[i] >> j) & 1;
              ^