View Compilation Error

0_0_23178062_19459.cpp: In function 'int main()':
0_0_23178062_19459.cpp:4:18: error: expected initializer before 'n'
  unsigned _int64 n,s;
                  ^
0_0_23178062_19459.cpp:5:23: error: 'n' was not declared in this scope
  while(scanf("%I64u",&n)!=EOF)
                       ^
0_0_23178062_19459.cpp:7:3: error: 's' was not declared in this scope
   s=((n*(n+1)/2%10000)*(n*(n+1)/2%10000))%10000;//最后四位
   ^