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#include <cstdio>
#include <cstring>

using namespace std;

#define MAX 1000100

typedef long long I;

char b[3][MAX];
I r;
I p0;

int main() {
    scanf(" %s %s %s ", b[0],b[1],b[2]);
    int n = strlen(b[0]);
    for(int i=0;i<3;i++)
        for(int j=0;j<n;j++) b[i][j]-='0';

    I t=0;
    for(int i=n-1;i >= 0;i--) {
        if(b[0][i] + b[1][i] + t == b[2][i]) {
            p0++;
            t=0;
            r+=p0;
        } else if (b[0][i] + b[1][i] + t == b[2][i] + 10) {
            t = 1;
        } else if (t == 1 && b[0][i] + b[1][i] == b[2][i]) {
            t=0;
            p0=1;
            r+=p0;
        } else if (t == 1 && b[0][i] + b[1][i] == b[2][i] + 10) {
            t=1;
            p0=0;
        } else { 
            p0=0;
            t=0;
        }
//        fprintf(stderr, "%d: p0:%lld t:%lld r:%lld  %d+%d=%d\n",i,p0,t,r,int(b[0][i]), int(b[1][i]), int(b[2][i]));
    }

    printf("%lld\n",r);
}