import sys
ctr=0
up=raw_input()
tocal=raw_input()
while ctr!=int(up):
    l=tocal.split(' ')
    num1=(l[0])[::-1]
    num2=(l[1])[::-1]
    while int(num1)%10 ==0 or int(num2)%10==0:
        if num1%10==0:
            num1=num1[:-1]
        elif num2%10==0:
            num2=num2[:-1]
            
                
    sum=int(num1)+int(num2)
    while sum%10==0:
        sum=int(str(sum)[:-1])
        
    rsum=str(sum)[::-1]
    
    print rsum
    ctr+=1
    tocal=raw_input()

sys.exit(0)