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

#define int long long
const int oo = 1e9 + 7;

void solve() {
    string a, b, c; cin >> a >> b >> c;
    int n = (int)a.size();

    vector dp(n+1, vector<int>(2));
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        int d = a[i - 1] - '0' + b[i - 1] - '0';
        for (int carry = 0; carry < 2; carry++) {
            if ((d + carry)%10 == c[i - 1] - '0') {
                dp[i][carry] = dp[i - 1][d + carry >= 10 ? 1 : 0];
                if (d + carry < 10) {
                    dp[i][carry]++;
                }
            }
        }
        ans += dp[i][0];
    }
    cout << ans << endl;
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    solve();

    return 0;
}