/in/foo.c: In function 'main':
/in/foo.c:9:5: error: 'i' undeclared (first use in this function)
    9 | for(i=0;i<n;++i)
      |     ^
/in/foo.c:9:5: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:12:21: error: expected ';' before '}' token
   12 |         sum=sum+part
      |                     ^
      |                     ;
   13 |         }
      |         ~