include[HTML_REMOVED]
using namespace std;
int ans;
void chak(int i){
while(i!=0){
if(i%10==2){
ans;
}
i=i/10;
}
}
int main(){
int star,end;
scanf(“%d %d”,&star,&end);
for(int i=star; i<=end; i){
chak(i);
}
cout<<ans<<endl;
return 0;
}