foo.cc: In function ‘int main()’:
foo.cc:7:18: error: expected ‘;’ before ‘<=’ token
    7 |     for(int i=1,i<=n;i++)
      |                  ^~
      |                  ;
foo.cc:7:18: error: expected primary-expression before ‘<=’ token
    7 |     for(int i=1,i<=n;i++)
      |                  ^~