View Compilation Error

0_0_30213449_3948.cpp: In function 'int main()':
0_0_30213449_3948.cpp:9:5: error: 'string' was not declared in this scope
     string in, leave;
     ^
0_0_30213449_3948.cpp:11:12: error: 'cin' was not declared in this scope
     while (cin >> N >> in >> leave) {
            ^
0_0_30213449_3948.cpp:11:24: error: 'in' was not declared in this scope
     while (cin >> N >> in >> leave) {
                        ^
0_0_30213449_3948.cpp:11:30: error: 'leave' was not declared in this scope
     while (cin >> N >> in >> leave) {
                              ^