#include <iostream>
using namespace std;
#define maxc 5000

int N, V[10];
int A[maxc], B[maxc], C[maxc];

void mul() {
      int i, j, t, C[maxc];
      memset(C, 0, sizeof(C));
      for (i = 1; i <= A[0]; i++)
      {
              for (t=0, j=1; j <= B[0] || t; j++, t/=10)
                      C[i+j-1]=(t+=C[i+j-1]+A[i]*B[j])%10;
              if (i + j - 2 > C[0]) C[0] = i + j - 2;
      }
      memcpy(A, C, sizeof(C));
}

int main() {
    FILE *f1=fopen("prod.in", "r"), *f2=fopen("prod.out", "w");
    int i, j, p, q;
    for(i=1; i<=9; i++) {
         fscanf(f1, "%d", &V[i]);
         N += V[i];
    }
    if(N % 2 == 0) {
         while(1) { };
         A[0] = B[0] = N/2;
         int laB = 0;
         int nrA = N/2, nrB = N/2;
         
         for(i=9; i>=1; i--) {
              while(V[i]) {
                   if(laB) {
                        B[nrB] = i;
                        nrB--;
                        laB = 0;
                   }
                   else {
                        A[nrA] = i;
                        nrA--;
                        laB = 1;
                   }
                   V[i]--;
              }
         }
    }
    
    mul();
    
    for(i=A[0]; i>=1; i--) {
         fprintf(f2, "%d", A[i]);
    }
    fclose(f1); fclose(f2);
    return 0;
}