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#include <iostream>
#include <string>

using namespace std;
typedef long long ll;

string a, b, w;

enum TrackingType {
    NotTracking,
    TrackingCarry
};


ll R = 0;
int last_end = -2;
int reps = 1;


void emit(int begin, int end) {
    //cout << "begin=" << begin << " end=" << end << '\n';
    if (last_end + 1 == begin)
        reps++;
    else {
        reps = 1;
    }
    R += reps;

    last_end = end;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    cin >> a >> b >> w;
    int L = a.length();
    auto state = NotTracking;
    int begin = -1;

    for (auto i=0; i<L; i++) {
        auto c = a[i]-'0'+b[i]-'0'-w[i]+'0';
        //cout << '\n';
        //cout << "state = " << state <<'\n';
        //cout << "c=" << c << '\n';
        
        if (c == 0) {
            state = NotTracking;
            begin = i;
            emit(i,i);
        }                
        
        switch (state) {
            case NotTracking:
                if (c == -1) {
                    state = TrackingCarry;
                    begin = i;
                }
                break;
            case TrackingCarry:
                if (c == 10) {
                    state = NotTracking;
                    emit(begin, i);
                }
                if (c!=10 && c!=9)
                    state = NotTracking;
                if (c == -1) {
                    state = TrackingCarry;
                    begin = i;
                }

                break;
        }
        //cout << "state = " << state <<'\n';

    }
    //cout << "state = " << state <<'\n';

    //cout << " reps = " << reps << '\n';

    cout<<R<<'\n';

    return 0;
}