include

using namespace std; int main(){

int a,b,c,d,S;
cin>>a>>b>>c>>d>>S;
{
		if(a+b==S||a+c==S||a+d==S||b+c==S||c+d==S||b+d==S){cout<<"1";}
		else {cout<<"-1";}
}
return 0;

}