Power function to calculate long powers with mod
def power ( x , y , p ) : NEW_LINE INDENT res = 1 NEW_LINE x = x % p NEW_LINE if ( x == 0 ) : NEW_LINE INDENT return 0 NEW_LINE DEDENT while ( y > 0 ) : NEW_LINE INDENT if ( y & 1 ) : NEW_LINE INDENT res = ( res * x ) % p NEW_LINE DEDENT y = y >> 1 NEW_LINE x = ( x * x ) % p NEW_LINE DEDENT return res NEW_LINE DEDENT