n = STDIN.gets.to_i
while n > 0

	line = STDIN.gets
	line =~ /(\d+)/
	a = $1.to_i
	
	line = STDIN.gets
	line =~ /(\d+)/
	b = $1.to_i
	
	sum = a + b
	
	if(sum >= 10**80)
		puts "overflow"
	else
		puts sum
	end

	n -= 1
end