View Compilation Error

0_0_34062400_32546.c: In function 'main':
0_0_34062400_32546.c:4:34: error: 'EOF' undeclared (first use in this function)
     while((scanf("%d %d",&a,&b)!=EOF)&&(a!=0||b!=0));
                                  ^
0_0_34062400_32546.c:4:34: note: each undeclared identifier is reported only once for each function it appears in