View Compilation Error

0_0_20926844_19606.cpp: In function 'int main()':
0_0_20926844_19606.cpp:8:1: error: 'cout' was not declared in this scope
 cout << a + b << endl;
 ^
0_0_20926844_19606.cpp:8:18: error: 'endl' was not declared in this scope
 cout << a + b << endl;
                  ^