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#include <bits/stdc++.h>
using namespace std;

const int ASCII_0 = 48;

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    string a, b, c;

    int n;

    cin >> a >> b >> c;

    n = a.length();

    long long result = 0;

    long long prev_count = 0;
    long long prev_carry = 0;
    long long curr_count, curr_carry;

    int sub_a, sub_b, sub_c;

    for(int i=n-1; i>=0; i--) {
        sub_a = a.at(i) - ASCII_0;
        sub_b = b.at(i) - ASCII_0;
        sub_c = c.at(i) - ASCII_0;

        int sum = sub_a + sub_b;

        if(sum == sub_c) {
            curr_count = prev_count + 1;
            curr_carry = 0;
        } else if (sum % 10 == sub_c) {
            curr_count = 0;
            curr_carry = prev_count + 1;
        } else if (prev_carry != 0 && sum + 1 == sub_c) {
            curr_count = prev_carry;
            curr_carry = 0;
        } else if (prev_carry != 0 && (sum + 1) % 10 == sub_c) {
            curr_count = 0;
            curr_carry = prev_carry;
        } else {
            curr_count = 0;
            curr_carry = 0;
        }

        result += curr_count;

        prev_count = curr_count;
        prev_carry = curr_carry;
    }

    cout << result <<"\n";
}