#include<bits/stdc++.h>
using namespace std;
int a1,b1,c1,a2,b2,c2,ans;
int main(){
    cin>>a1>>b1>>c1>>a2>>b2>>c2;
    if(a1<a2){
        ans+=a2-a1;
        b1-=(a2-a1)*11;
        a1=a2;
    }
    if(c1<c2){
        ans+=(c2-c1+8)/9;
        b1-=(c2-c1+8)/9;
        c2+=(c2-c1+8)/9*9;
    }
    if(b1<b2&&a1>a2){
        if(b1+(a1-a2)*9<b2){
            ans+=(a1-a2);
            b1+=(a1-a2)*9;
            a1=a2;
        }
        else{
            ans+=(b2-b1+8)/9;
            a1-=(b2-b1+8)/9;
            b1+=(b2-b1+8)/9*9;
        }
    }
    if(b1 < b2){
        if(b1+(c1-c2)/11>=b2){
            ans+=(c1 - c2)/11;
            b1+=(c1 - c2)/11;
            c1-=(c1 - c2)/11*11;
        }
    }
    cout<<(b1 >= b2?ans:-1); 
    return 0;
}