Language: C

i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}

Compiler output:
main.c:1:1: warning: data definition has no type or storage class
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      | ^
main.c:1:1: error: type defaults to 'int' in declaration of 'i' [-Wimplicit-int]
main.c:1:3: error: type defaults to 'int' in declaration of 'x' [-Wimplicit-int]
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |   ^
main.c:1:5: error: type defaults to 'int' in declaration of 'y' [-Wimplicit-int]
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |     ^
main.c:1:7: error: type defaults to 'int' in declaration of 'z' [-Wimplicit-int]
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |       ^
main.c:1:9: error: return type defaults to 'int' [-Wimplicit-int]
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |         ^~~~
main.c: In function 'main':
main.c:1:9: error: type of 'a' defaults to 'int' [-Wimplicit-int]
main.c:1:31: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |                               ^~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
main.c:1:31: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |                               ^~~~~
main.c:1:31: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:1:81: error: expected ':' before ';' token
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |                                                                                 ^
      |                                                                                 :
main.c:1:82: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |                                                                                  ^~~~~~
main.c:1:82: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:82: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
main.c:1:82: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:111: error: implicit declaration of function 'exit' [-Wimplicit-function-declaration]
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |                                                                                                               ^~~~
main.c:1:1: note: include '<stdlib.h>' or provide a declaration of 'exit'
  +++ |+#include <stdlib.h>
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
main.c:1:111: warning: incompatible implicit declaration of built-in function 'exit' [-Wbuiltin-declaration-mismatch]
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      |                                                                                                               ^~~~
main.c:1:111: note: include '<stdlib.h>' or provide a declaration of 'exit'
main.c:1:1: error: expected declaration or statement at end of input
    1 | i,x,y,z;main(a){for(;i++<=9;){scanf("%d",&a);x<a?z=y,y=x,x=a:y<a?z=y,y=a:z<a?z=a;printf("%d\n%d\n%d\n",x,y,z);exit(0);}
      | ^