View Compilation Error

0_0_30228941_11483.cpp: In function 'int main()':
0_0_30228941_11483.cpp:7:2: error: 'cin' was not declared in this scope
  cin>>T;
  ^
0_0_30228941_11483.cpp:11:19: error: 'scanf' was not declared in this scope
   scanf("%s%s",a,b);
                   ^
0_0_30228941_11483.cpp:32:3: error: 'cout' was not declared in this scope
   cout<<sum<<endl;
   ^
0_0_30228941_11483.cpp:32:14: error: 'endl' was not declared in this scope
   cout<<sum<<endl;
              ^