View Compilation Error

0_0_16747486_9952.cpp: In function 'int main()':
0_0_16747486_9952.cpp:7:1: error: '__int' was not declared in this scope
 __int a,b;
 ^
0_0_16747486_9952.cpp:10:7: error: expected ';' before 'sum'
 __int sum=0;
       ^
0_0_16747486_9952.cpp:11:6: error: 'a' was not declared in this scope
 cin>>a>>b;
      ^
0_0_16747486_9952.cpp:11:9: error: 'b' was not declared in this scope
 cin>>a>>b;
         ^
0_0_16747486_9952.cpp:12:1: error: 'sum' was not declared in this scope
 sum=a+b;
 ^