#include<iostream> #include<cstdio> //scanf()\printf() #include<cstring> #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int m,n,s=0; cin>>m>>n; for(int i=m;i<=n;i++){ if(i%13==0) s+=i; } cout<<s; }