View Compilation Error

0_0_34905379_28011.cpp: In function 'int main()':
0_0_34905379_28011.cpp:5:8: error: storage size of 'a' isn't known
  int a[];
        ^
0_0_34905379_28011.cpp:6:7: error: expected primary-expression before ';' token
  cin>>;
       ^
0_0_34905379_28011.cpp:7:18: error: 'b' was not declared in this scope
  printf("%d\n",a+b);
                  ^