/in/foo.c: In function 'main':
/in/foo.c:8:3: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   if (n=1)
   ^~
/in/foo.c:11:2: warning: this 'else' clause does not guard... [-Wmisleading-indentation]
  else
  ^~~~
/in/foo.c:13:3: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else'
   for (i=3;i<=n;i++)
   ^~~