#include <stdio.h>
#include <math.h>

int N,A,B,K;
int v[101];
long fact (int n)
{
int i;
long p=1;
for (i=2;i<=n;i++)
    p*=i;
return p;
}

int min (int x1,int x2)
{
if (x1<x2) return x1;
return x2;
}

int main ()
{
int i,j;
freopen ("pavare2.in","r",stdin);
freopen ("pavare2.out","w",stdout);
scanf ("%d %d %d %d",&N,&A,&B,&K);

printf ("%ld\n",fact(N)/min(A,B));
j=0;
for (i=1;i<=N;i++)
    {
    j++;
    if (j==A+1)
       {
       printf ("%d",1);
       j=0;
       }
    else printf ("%d",0);
    }
fclose(stdin);
fclose(stdout);
return 0;
}