2003=4*500+3
2 la puterea 2003 are ultima cifra 8
3 la puterea 2003 are ultima cifra 7
4 laputerea 2003 are ultima cifra 4
5 la orice putere are ultima cifra 5
6 la orice putere are ultima cifra 6
7 la puterea 2003 are ultima cifra 3
...8+...7+...4+...5+...6+....3=....3
