#include using namespace std; #define F first #define S second #define R cin>> #define ll long long #define ln cout<<'\n' #define in(a) insert(a) #define pb(a) push_back(a) #define pd(a) printf("%.10f\n",a) #define mem(a) memset(a,0,sizeof(a)) #define all(c) (c).begin(),(c).end() #define iter(c) __typeof((c).begin()) #define rrep(i,n) for(ll i=(ll)(n)-1;i>=0;i--) #define REP(i,m,n) for(ll i=(ll)(m);i<(ll)(n);i++) #define rep(i,n) REP(i,0,n) #define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++) ll check(ll n,ll m,ll x,ll y){return x>=0&&x=0&&yvoid pr(const A &a,const B&...b){cout<void PR(A a,ll n){rep(i,n)cout<<(i?" ":"")< P; void Main() { ll n; cin >> n; ll a[n],b[n]; rep(i,n) cin >> a[i]; rep(i,n) cin >> b[i]; ll d[n]; rep(i,n) d[i]=a[i]-b[i]; sort(d,d+n); ll ans=d[n-1]; rep(i,n) d[i]-=ans; ll sum=0; rep(i,n) sum-=d[i]; if(sum==ans*2) pr(ans); else pr(-1); } int main(){ios::sync_with_stdio(0);cin.tie(0);Main();return 0;}