View Compilation Error

0_0_32018327_14731.cpp: In function 'int main()':
0_0_32018327_14731.cpp:20:3: error: 'cin' was not declared in this scope
   cin >> cai[i].a >> cai[i].b >> cai[i].c;
   ^
0_0_32018327_14731.cpp:23:2: error: 'cout' was not declared in this scope
  cout << fixed << setprecision(1) << sum << endl;
  ^
0_0_32018327_14731.cpp:23:45: error: 'endl' was not declared in this scope
  cout << fixed << setprecision(1) << sum << endl;
                                             ^