View Compilation Error

0_0_17677080_4224.cpp:20:2: error: expected unqualified-id before 'while'
  while(scanf("%ld",&n)>0)
  ^
0_0_17677080_4224.cpp:30:2: error: expected unqualified-id before 'return'
  return 0;
  ^
0_0_17677080_4224.cpp:31:1: error: expected declaration before '}' token
 }
 ^