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#include <iostream>
using namespace std;

//#define DEBUG

int main() {
    string a, b, c;
    cin >> a >> b >> c;

    #ifdef DEBUG
    cout << a << endl << b << endl << c << endl;
    #endif // DEBUG

    int i=a.size()-1, carry = 0, endings=0;
    long long result = 0;

    while (i >= 0) {
        #ifdef DEBUG
        cout << i << endl;
        #endif // DEBUG
        int x = a[i] - '0', y = b[i] - '0', z = c[i] - '0';
        int sum = x+y+carry;
        if (sum % 10 != z) {
            #ifdef DEBUG
            cout << "LIPA" << endl;
            #endif // DEBUG
            endings = 0;
            if (!carry) i--;
            carry = 0;
            continue;
        }
        if (!carry) {
            #ifdef DEBUG
            cout << "POTENTIAL ENDING" << endl;
            #endif // DEBUG
            endings++;
        }
        if (sum < 10) {
            #ifdef DEBUG
            cout << i << " HAS " << endings << " endings" << endl;
            #endif // DEBUG
            result += endings;
        }
        carry = sum / 10;
        i--;
    }

    cout << result << endl;
}