View Compilation Error

0_0_22376672_3565.cpp: In function 'int main()':
0_0_22376672_3565.cpp:7:1: error: 'sum' was not declared in this scope
 sum=a+b
 ^
0_0_22376672_3565.cpp: At global scope:
0_0_22376672_3565.cpp:9:1: error: expected declaration before '}' token
 }
 ^