RSA algorithm question

this is the question - 66 ^ 77 mod 119
answer is - 19
how this 19 comes ?
what is the simple method to take this answer ?
in advance please...........

Use repeated squaring.

66^2 = 72 (mod 119)
66^4 = 72^2 = 67 (mod 119)
66^8 = 67^2 = 86 (mod 119)
66^16 = 86^2 = 18 (mod 119)
66^32 = 18^2 = 86 (mod 119)
66^64 = 86^2 = 18 (mod 119).

Now, write the exponent as a sum of powers of 2:
77 = 64 + 8 + 2 + 1.

Therefore,
66^77 = 66^64 * 66^8 * 66^4 * 66^1
.........= 18 * 86 * 67 * 66
.........= 19 (mod 119).

I hope this helps!