View Compilation Error

0_0_21475774_403.cpp:1:3: error: stray '#' in program
 1 #include <iostream>
   ^
0_0_21475774_403.cpp:1:1: error: expected unqualified-id before numeric constant
 1 #include <iostream>
 ^
0_0_21475774_403.cpp:3:2: error: expected unqualified-id before numeric constant
  3 int n, m;
  ^
0_0_21475774_403.cpp:4:2: error: expected unqualified-id before numeric constant
  4 int arr[1000];
  ^
0_0_21475774_403.cpp:5:2: error: expected unqualified-id before numeric constant
  5 
  ^
0_0_21475774_403.cpp:13:1: error: expected unqualified-id before numeric constant
 13 int lcm(int a, int b)  //注意这里不能用a*b/gcd(a,b)，数据会溢出
 ^
0_0_21475774_403.cpp:17:1: error: expected unqualified-id before numeric constant
 17 int main()
 ^