/in/foo.cc: In function 'int main()':
/in/foo.cc:14:6: warning: 's' may be used uninitialized in this function [-Wmaybe-uninitialized]
     s=s+(b-b%100);
     ~^~~~~~~~~~~~
/in/foo.cc:9:8: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
     b=b+300-a;
       ~^~~~