#include<iostream> using namespace std; int main() { int i,J,u,uu,uuu,uuuu,S=0; cin>>i>>J; for(int n=i;n<=J;n++){ u=n%10; uu=(n-u)/10%10; uuu=(n-u-10*uu)/100%10; uuuu=(n-u-10*uu-100*uuu)/1000; if((u+uu+uuu+uuuu)%2==1){ S++; } } cout<<S; return 0;}