#include<stdio.h>
#include<stdlib.h>
#define N 200001
long n,m,a[N],b[N],i,*g[N],deg[N]={0},c[N]={0},s[N],ss,v[N]={0},l[N],q[N],sq=0,j,k,r,nr,ind,e[N],*d[N],ok=0,st[N],u=0;
int p[N],viz[N]={0};

void tarjan(long i,long *nr,long *ind)
{long j,r;
s[++ss]=i;
if(v[i]==0)
      v[i]=1;
c[i]=(*ind);
l[i]=(*ind)++;
for(j=0;j<deg[i];j++)
if(c[g[i][j]]==0)
      {tarjan(g[i][j],nr,ind);
      if(l[i]>l[g[i][j]])
             l[i]=l[g[i][j]];}
else
      if(v[g[i][j]]==1&&l[i]>c[g[i][j]])
             l[i]=c[g[i][j]];
if(c[i]==l[i])
      {sq=0;
      while(ss)
             {r=s[ss--];
             if(r!=i&&v[r]==1)
                     q[sq++]=r,v[r]=2;
             else
                     break;}
      if(v[i]==1)
             v[i]=2,q[sq++]=i;
      if(sq>0)
             {d[++(*nr)]=(long*)malloc(sq*sizeof(long));
             e[(*nr)]=sq;
             for(j=0;j<sq;j++)
                     d[(*nr)][j]=q[j];}}}

void ts(long t,long *u)
{long i,j,k,l;
viz[t]=1;
for(k=0;k<e[t];k++)
       {for(l=0;l<deg[d[t][k]];l++)
                  {for(i=1;i<=nr;i++)
                  if(!viz[i])
                             {for(j=0;j<e[i];j++)
                             if(d[i][j]==g[d[t][k]][l])
                                       ts(i,u);}}}
st[++(*u)]=t;}

int main()
{freopen("2sat.in","r",stdin);
freopen("2sat.out","w",stdout);
scanf("%ld%ld",&n,&m);
for(i=1;i<=m;i++)
       {scanf("%ld%ld",&a[i],&b[i]);
       if(a[i]<0)
              deg[n-a[i]]++;
       else
              deg[a[i]]++;
       if(b[i]<0)
              deg[n-b[i]]++;
       else
              deg[b[i]]++;}
for(j=1;j<=2*n;deg[j++]=0)
       {g[j]=(long*)malloc(deg[j]*sizeof(long));
       p[j]=2;}
for(k=1;k<=m;k++)
       {if(a[k]<0)
              a[k]=n-a[k];
       if(b[k]<0)
              b[k]=n-b[k];
       if(a[k]>n)
             g[a[k]-n][deg[a[k]-n]++]=b[k];
       else
             g[n+a[k]][deg[n+a[k]]++]=b[k];
       if(b[k]>n)
             g[b[k]-n][deg[b[k]-n]++]=a[k];
       else
             g[n+b[k]][deg[n+b[k]]++]=a[k];}
nr=ind=ss=0;
for(i=1;i<=2*n;i++)
if(!c[i])
      tarjan(i,&nr,&ind);
for(r=1;r<=nr;r++)
if(!viz[r])
      {ts(r,&u);
      k=1;
      for(i=1;i<=u;i++)
              {for(j=0;j<e[st[i]];j++)
              if(p[d[st[i]][j]]==2)
                      {p[d[st[i]][j]]=k;
                      if(d[st[i]][j]>n)
                              p[d[st[i]][j]-n]=!k;
                      else
                              p[d[st[i]][j]+n]=!k;}
              else
                      k=p[d[st[i]][j]];}
      u=0;}
for(i=1;i<=m;i++)
      {if(a[i]<0)
               a[i]=n-a[i];
      if(b[i]<0)
               b[i]=n-b[i];
      if(!p[a[i]]&&!p[b[i]])
               {ok=1;
               break;}}
if(!ok)
      {for(i=1;i<=n;i++)
              printf("%d ",p[i]);}
else
      printf("-1");
fclose(stdin);
fclose(stdout);
return 0;}