View Compilation Error

0_0_20683746_21521.cpp: In function 'int main()':
0_0_20683746_21521.cpp:4:28: error: 'eof' was not declared in this scope
 While(scanf("%d%d",&a,&b)!=eof){
                            ^
0_0_20683746_21521.cpp:4:31: error: 'While' was not declared in this scope
 While(scanf("%d%d",&a,&b)!=eof){
                               ^