View Compilation Error

0_0_19237047_22229.cpp: In function 'int main()':
0_0_19237047_22229.cpp:7:17: error: 'a' was not declared in this scope
   printf("%d\n",a+b);
                 ^
0_0_19237047_22229.cpp:7:19: error: 'b' was not declared in this scope
   printf("%d\n",a+b);
                   ^