#include using namespace std; typedef long long ll; typedef pair P; #define REP(i,n) for(ll i=0;i> N >> S >> T >> K; vector a(N); ll m=10000000000,x; REP(i,N){ cin >> a[i]; if(m>a[i]){ x=i; m=a[i]; } } ll p=a[S-1],q=a[T-1]; if(p+q<=K) cout << 1 << endl; else if(x==S-1 || x==T-1) cout << -1 << endl; else if(m+p<=K && m+q<=K) cout << 2 << endl; else cout << -1 << endl; return 0; }