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#include<bits/stdc++.h>

using namespace std;

const int DEF = -1;

int main() {
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(NULL);
		
	string a, b, c;
	cin >> a >> b >> c;
	
	int n = a.size();
	
	vector<int> yc(n, DEF);
	vector<int> yn(n, DEF);
	
	
	for (int i = n - 1; i >= 0; i--) {
		int sum = (int)(a[i] - '0') + (int)(b[i] - '0');
		int exp_sum = (int) (c[i] - '0');
		
		if (sum == exp_sum) {
			yn[i] = 0;
		} else if (sum == exp_sum + 10) {
			yn[i] = 1;
		} else if (sum + 1 == exp_sum) {
			yc[i] = 0;
		} else if (sum + 1 == exp_sum + 10) {
			yc[i] = 1;
		}
	}
	
	long long pos_ends = 0LL;
	bool carry = false;
	long long total = 0LL;
	
	for (int i = n-1; i >= 0; i--) {
		if (carry) {
			if (yc[i] == DEF) {
				pos_ends = 0LL;
				carry = false;
				if (yn[i] != DEF) {
					pos_ends++;
					carry = (yn[i] == 1);
					if (!carry) {
						total += pos_ends;
					}
				}
			} else {
				carry = (yc[i] == 1);
				if (!carry) {
					total += pos_ends;
				}
			}
		} else {
			if (yn[i] == DEF) {
				pos_ends = 0LL;
				carry = false;
				continue;
			} else {
				pos_ends++;
				carry = (yn[i] == 1);
				if (!carry) {
					total += pos_ends;
				}
			}
		}
	}
	
	cout << total;
	
}