foo.cc: In function ‘int main()’:
foo.cc:7:22: error: expected ‘;’ before ‘<=’ token
    7 |         for(int i=a,i<=b;i++)
      |                      ^~
      |                      ;
foo.cc:7:22: error: expected primary-expression before ‘<=’ token
    7 |         for(int i=a,i<=b;i++)
      |                      ^~