Function to implement fast exponentiation
def binpow ( a , b ) : NEW_LINE INDENT res = 1 NEW_LINE while ( b > 0 ) : NEW_LINE INDENT if ( b % 2 == 1 ) : NEW_LINE INDENT res = res * a NEW_LINE DEDENT a = a * a NEW_LINE b //= 2 NEW_LINE DEDENT return res NEW_LINE DEDENT