foo.c: In function 'main':
foo.c:7:23: error: expected ';' before 'for'
    7 |         scanf("%d",&x)
      |                       ^
      |                       ;
    8 |                 for(int n=2;n<=x;n++)
      |                 ~~~    
foo.c:6:13: warning: unused variable 'num' [-Wunused-variable]
    6 |         int num=0;
      |             ^~~

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