#include using namespace std; #define rep(i,a,b) for(LL i = a;ib; i--) #define INF ((1LL<<62)-(1LL<<31)) #define ooki 9,223,372,036,854,775,807 #define tii -9,223,372,036,854,775,808 typedef long long LL; int main(){ int a,b,c,d; cin >> a >> b >> c >> d; if(a>c){cout<<"null"<