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#include <bits/stdc++.h>

using namespace std;

int main() {
    cin.tie(nullptr); ios_base::sync_with_stdio(false);
    string a, b, c;
    cin >> a >> b >> c;
    
    int carryover = 0;
    long long ongoing = 0;
    long long result = 0;
    for(int i = a.length()-1; i >= 0; i--) {
        if(a[i]-'0'+b[i]-'0' == c[i]-'0') {
            if(carryover == 1) {
                ongoing = 0;
                carryover = 0;
            }
            ongoing++;
            result += ongoing;
        }
        else if(carryover+a[i]-'0'+b[i]-'0' == c[i]-'0') {
            carryover = 0;
            ongoing++;
            result += ongoing;
        } else if(a[i]-'0'+b[i]-'0' == 10 + c[i] - '0') {
            if(carryover == 1) {
                ongoing = 0;
            }
            carryover = 1;
        } else if(carryover+a[i]-'0'+b[i]-'0' == 10 + c[i] - '0') {
            carryover = 1;
        } else {
            carryover = 0;
            ongoing = 0;
        }
    }

    cout << result << '\n';
}