/in/foo.cc: In function 'int bs(int, int)':
/in/foo.cc:5:9: warning: unused variable 'n' [-Wunused-variable]
     int n = 0, ys, ls = 0 , lsb = b;
         ^
/in/foo.cc:20:25: warning: 'ys' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return (ys*(a/ys)*(b/ys));
                       ~~^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:20:25: warning: 'ys' may be used uninitialized in this function [-Wmaybe-uninitialized]
     return (ys*(a/ys)*(b/ys));
                       ~~^~~~
/in/foo.cc:5:16: note: 'ys' was declared here
     int n = 0, ys, ls = 0 , lsb = b;
                ^~