View Compilation Error

0_0_28657475_3666.cpp: In function 'int main()':
0_0_28657475_3666.cpp:8:2: error: expected unqualified-id before 'double'
  double x, y, a, b;
  ^
0_0_28657475_3666.cpp:9:16: error: 'x' was not declared in this scope
  while (cin >> x >> y >> a >> b)
                ^
0_0_28657475_3666.cpp:9:21: error: 'y' was not declared in this scope
  while (cin >> x >> y >> a >> b)
                     ^
0_0_28657475_3666.cpp:9:26: error: 'a' was not declared in this scope
  while (cin >> x >> y >> a >> b)
                          ^
0_0_28657475_3666.cpp:9:31: error: 'b' was not declared in this scope
  while (cin >> x >> y >> a >> b)
                               ^