View Compilation Error

0_0_7758174_26970.cpp:3: error: `string' does not name a type
0_0_7758174_26970.cpp: In function `int main()':
0_0_7758174_26970.cpp:38: error: `string' undeclared (first use this function)
0_0_7758174_26970.cpp:38: error: (Each undeclared identifier is reported only once for each function it appears in.)
0_0_7758174_26970.cpp:38: error: expected `;' before "a"
0_0_7758174_26970.cpp:39: error: `cin' undeclared (first use this function)
0_0_7758174_26970.cpp:39: error: `a' undeclared (first use this function)
0_0_7758174_26970.cpp:39: error: `b' undeclared (first use this function)
0_0_7758174_26970.cpp:40: error: `cout' undeclared (first use this function)
0_0_7758174_26970.cpp:40: error: `d' undeclared (first use this function)
0_0_7758174_26970.cpp:40: error: `add' undeclared (first use this function)
0_0_7758174_26970.cpp:40: error: `endl' undeclared (first use this function)