#include <iostream>
using namespace std;
 
int main() {
	// Introduc variabilele a, b, c şi x;
	int a, b, c, x;
	// Citesc a, b, c, x;
	cin >> a >> b >> c >> x;
 
	if (c != x % 10) cout <<"NU";
 
	if (c == x % 10) {// verificam "c"
 
 
	// Introduc variabila “cnt” sa numar cifrele;
	int cnt = 0;
	// parcurg x;
	int x_copy;
	while (x > 0) {
			++cnt;
		x_copy = x;// verificam "b" introducand o variabila copie a lui x 
		//pentru a mentine penultima valoare a lui x
		x /= 10;
 
	}
		if (b == x_copy)
			cout <<"DA";
 
		//cout << cnt;// verificam "a"
	}
 
	return 0;
}

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

NiA0IDIgNDg5NjQzCg==

6 4 2 489643