/in/foo.c: In function 'main':
/in/foo.c:6:10: warning: format '%d' expects argument of type 'int *', but argument 2 has type 'int' [-Wformat=]
  scanf("%d",n);
          ^
/in/foo.c:7:8: warning: statement with no effect [-Wunused-value]
   for(i==1;i<=n;i++)
       ~^~~
/in/foo.c:9:4: error: expected ';' before 'sum'
    sum=sun+pow(i,2);
    ^~~