View Compilation Error

0_0_13385941_7464.cpp: In function 'int main()':
0_0_13385941_7464.cpp:4:2: error: 'string' was not declared in this scope
0_0_13385941_7464.cpp:4:9: error: expected ';' before 'a'
0_0_13385941_7464.cpp:6:8: error: 'cin' was not declared in this scope
0_0_13385941_7464.cpp:6:13: error: 'a' was not declared in this scope
0_0_13385941_7464.cpp:23:11: error: 'cout' was not declared in this scope
0_0_13385941_7464.cpp:23:20: error: 'endl' was not declared in this scope