1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
#include <bits/stdc++.h>
using namespace std;
#define fwd(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) fwd(i, 0, n)
#define all(X) X.begin(), X.end()
#define sz(X) int(size(X))
#define pb push_back
#define eb emplace_back
#define st first
#define nd second
using pii = pair<int, int>; using vi = vector<int>;
using ll = long long; using ld = long double;
#ifdef LOC
auto SS = signal(6, [](int) { *(int *)0 = 0; });
#define DTP(x, y) auto operator << (auto &o, auto a) -> decltype(y, o) { o << "("; x; return o << ")"; }
DTP(o << a.st << ", " << a.nd, a.nd);
DTP(for (auto i : a) o << i << ", ", all(a));
void dump(auto... x) { (( cerr << x << ", " ), ...) << '\n'; }
#define deb(x...) cerr << setw(4) << __LINE__ << ":[" #x "]: ", dump(x)
#else
#define deb(...) 0
#endif

void solve() {
    vector<vi> V(3);
    for(int i = 0; i < 3; i++) {
        string s;
        cin >> s;
        for(auto c: s){
            V[i].pb(c - '0');
        }
    }

    ll res = 0;
    int proper = 0;
    bool carry = false;
    for(int j = V[0].size() - 1; j >= 0; j--) {
        int p = V[0][j] + V[1][j] + carry;
        if (p % 10 == V[2][j]) {
            if(p < 10) {
                carry = false;
                proper++;
                res += proper;
            } else {
                carry = true;
            }
        } else {
            bool save = carry;
            carry = false;
            proper = 0;
            if(save) {
                // Let's try again :)
                j++;
                continue;
            }
        }
    }

    cout << res << "\n";
}

int32_t main() {
	cin.tie(0)->sync_with_stdio(0);
	cout << fixed << setprecision(10);

    solve();
}