View Compilation Error

0_0_19341549_4821.c: In function 'main':
0_0_19341549_4821.c:4:2: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'long'
  long long sum;
  ^
0_0_19341549_4821.c:5:20: error: 'n' undeclared (first use in this function)
  while(scanf("%d",&n)!=EOF){
                    ^
0_0_19341549_4821.c:5:20: note: each undeclared identifier is reported only once for each function it appears in
0_0_19341549_4821.c:6:3: error: 'sum' undeclared (first use in this function)
   sum=0;
   ^