/in/foo.c: In function 'main':
/in/foo.c:6:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
    6 |         for(i=2;i<n;i++);
      |         ^~~
/in/foo.c:7:9: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
    7 |         {  if(n%i==o)
      |         ^
/in/foo.c:7:20: error: 'o' undeclared (first use in this function)
    7 |         {  if(n%i==o)
      |                    ^
/in/foo.c:7:20: note: each undeclared identifier is reported only once for each function it appears in