View Compilation Error

0_0_7216868_5515.cpp: In function `int main()':
0_0_7216868_5515.cpp:6: error: `string' undeclared (first use this function)
0_0_7216868_5515.cpp:6: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_7216868_5515.cpp:6: error: expected `;' before "b"
0_0_7216868_5515.cpp:7: error: `cin' undeclared (first use this function)
0_0_7216868_5515.cpp:7: error: `b' undeclared (first use this function)
0_0_7216868_5515.cpp:7: error: `getline' undeclared (first use this function)
0_0_7216868_5515.cpp:16: error: `cout' undeclared (first use this function)
0_0_7216868_5515.cpp:21: error: `endl' undeclared (first use this function)