Kalkulator

for _ in range(int(input())):
    Test=input().split()
    if Test[0].isdigit() and Test[1].isdigit():
        print(int(Test[0])+int(Test[1]))
    elif Test[0].isdigit() or Test[1].isdigit():
        if Test[0].isdigit():
            numb=int(Test[0])
            print(Test[1][numb-1])
        else:
            numb=int(Test[1])
            print(Test[0][numb-1])
    else:
        print(Test[0]+Test[1])