/in/foo.c: In function 'main':
/in/foo.c:6:23: error: expected ';' before 'if'
    6 |         scanf("%d",&n)
      |                       ^
      |                       ;
    7 |         if(n>=80&&n<=100)
      |         ~~             
/in/foo.c:9:9: error: 'else' without a previous 'if'
    9 |         else if(n>=70&&n<=79)
      |         ^~~~
/in/foo.c:15:17: error: expected ';' before '}' token
   15 |         return 0
      |                 ^
      |                 ;
   16 | }
      | ~