View Compilation Error

0_0_33646963_30044.c: In function 'main':
0_0_33646963_30044.c:7:12: error: 'EOF' undeclared (first use in this function)
     while (EOF != scanf("%d %d %d %d%*c", &x, &y, &_x, &_y)) {
            ^
0_0_33646963_30044.c:7:12: note: each undeclared identifier is reported only once for each function it appears in