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

#define ll long long
#define st first
#define nd second
#define ld long double

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    string A, B, C;
    cin >> A >> B >> C;
    int n = A.size();
    vector<int> a (n), b (n), c (n), t (n, 0), s (n, 0);
    for (int i = 0; i < n; i++) {
        a[i] = A[i]-'0';
        b[i] = B[i]-'0';
        c[i] = C[i]-'0';
        s[i] = a[i]+b[i];
        if ((a[i]+b[i])%10==c[i]) {
            t[i] = 1;
        }
        if ((a[i]+b[i]+1)%10==c[i]) {
            t[i] = 2;
        }
    }
    ll in = n, l = 0, ans = 0;
    for (int i = n-1; i >= 0; i--) {
        if (t[i] != 1) {
            continue;
        }
        if (in > i) {
            int p = s[i]/10;
            l = s[i] < 10;
            in = i-1;
            while (in >= 0) {
                //cout << in << ' ' << s[in]+p << '\n';
                if ((s[in]+p)%10 == c[in]) {
                    if (s[in]+p > 9) {
                        p = 1;
                    }
                    else {
                        l++;
                        p = 0;
                    }
                }
                else {
                    in++;
                    break;
                }
                in--;
            }
            //cout << l << '\n';
        }
        ans += l;
        //cout << i << ' ' << l << ' ' << ans << '\n';
        l--;
    }
    cout << ans << '\n';
}