xy=b mod c
.....(x mod c)(y mod c)=b mod c
ex....
10*8 mod 7=80 mod 7=3
....(10 mod 7)*(8 mod 7)=3
x^y mod c=(x mod c)^(y mod d) ;d= etf(d)
etf kiyanne Euler Tortient function...
prime number (p) ekakata
etu(p)=p-1
ex..etu(7)=7-1=6;
aneth ewata prime factor kadanta oone...