View Compilation Error

0_0_16620310_14238.c: In function 'main':
0_0_16620310_14238.c:4:26: error: 'eof' undeclared (first use in this function)
    while(scanf("%d",&a)!=eof)
                          ^
0_0_16620310_14238.c:4:26: note: each undeclared identifier is reported only once for each function it appears in