View Compilation Error

0_0_26745113_24933.cpp: In function 'int main()':
0_0_26745113_24933.cpp:5:20: error: 'a' was not declared in this scope
  while(scanf("%d",&a)!=EOF)
                    ^
0_0_26745113_24933.cpp:19:2: error: expected ';' before '}' token
  }
  ^