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a = input()
b = input()
c = input()

n = len(a)

cnt = 0

i = n-1
while i >= 0:
# for i in range(n-1,-1,-1):
    # dig_a = int(a[i])
    # dig_b = int(b[i])
    # dig_c = int(c[i])


    # print(i,j,num_a[j:i],num_b[j:i],num_c[j:i])
    # summ = dig_a + dig_b

    # if summ == dig_c:
    #     cnt += 1
    #     remainder = 0
    # elif summ % 10 == dig_c:
    #     remainder = summ // 10
    # else:
    #     continue
    session_sum = 0
    session_cnt = 0
    remainder = 0
    cnt_j = 0
    for j in range(i,-1,-1):
        cnt_j += 1
        dig_a = int(a[j])
        dig_b = int(b[j])
        dig_c = int(c[j])


        # print(i,j,a[j],b[j],c[j], remainder)
        summ = dig_a + dig_b + remainder

        if summ == dig_c:
            # cnt += 1
            session_cnt += 1
            session_sum += session_cnt
            remainder = 0
            # print('session_cnt', session_cnt)
            # print('session_sum', session_sum)
        elif summ % 10 == dig_c:
            remainder = summ // 10
        elif (dig_a + dig_b == dig_c) or ((dig_a + dig_b) % 10 == dig_c):
            cnt_j -= 1
            break
        else:
            break


    cnt += session_sum
    i -= cnt_j


# print(a)
# print(b)
# print(c)

print(cnt)