Loop until one of the numbers have no digits remaining
while ( n1 > 0 and n2 > 0 ) : NEW_LINE INDENT sum1 += ( ( n1 % 10 ) * ( n2 % 10 ) ) ; NEW_LINE n1 = n1 // 10 ; NEW_LINE n2 = n2 // 10 ; NEW_LINE DEDENT return sum1 ; NEW_LINE