foo.c: In function 'main':
foo.c:5:13: error: expected identifier or '(' before numeric constant
    5 |         int 1|x,y,z,max;
      |             ^
foo.c:7:25: error: 'x' undeclared (first use in this function)
    7 |         scanf("%d%d%d",&x,&y,&z);
      |                         ^
foo.c:7:25: note: each undeclared identifier is reported only once for each function it appears in
foo.c:7:28: error: 'y' undeclared (first use in this function)
    7 |         scanf("%d%d%d",&x,&y,&z);
      |                            ^
foo.c:7:31: error: 'z' undeclared (first use in this function)
    7 |         scanf("%d%d%d",&x,&y,&z);
      |                               ^
foo.c:9:17: error: 'max' undeclared (first use in this function)
    9 |                 max=x;
      |                 ^~~

[Hydro](https://hydro.ac)提供评测服务