elementary number theory - $7777^{5555}$ divided by $191$. Find the remainder.

I've seen tons of examples of Fermat's little theorem and solved some it for smaller numbers, but I fail with this.

By Fermat's little theorem $7777^{190} \equiv 1\pmod{191}$

Then $7777^{5555} = 7777^{(190 \cdot 29)} \cdot 7777^{45} \equiv 1^{29} \cdot 7777^4\pmod{191}$

But after that I'm stuck.