View Compilation Error

0_0_36640984_4041.cpp: In function 'int main()':
0_0_36640984_4041.cpp:6:2: error: 'ios' has not been declared
  ios::sync_with_stdio(false);
  ^
0_0_36640984_4041.cpp:7:8: error: 'cin' was not declared in this scope
  while(cin>>a>>b) cout<<a+b<<'\n';
        ^
0_0_36640984_4041.cpp:7:19: error: 'cout' was not declared in this scope
  while(cin>>a>>b) cout<<a+b<<'\n';
                   ^