int main()
{
int kase,F,T,d[10009],u,i;
sieve(10002);
scanf("%d",&kase);
while(kase--)
{
scanf("%d %d",&F,&T);
bool vis[10009]={0};
q.push(F);
d[F]=0;
vis[F]=1;
while(!q.empty())
{
u=q.front();
q.pop();
for(i=0;i<c;i++)
{
if(!vis[a[i]])
if(check(u,a[i]))
d[a[i]]=d[u]+1,q.push(a[i]),vis[a[i]]=1;
}
}
if(vis[T])
printf("%d\n",d[T]);
else
printf("Impossible\n");
}
return 0;
}
bool solve(qi &l)
{
int t;
si r;
int i=1;
bool found=false;
while(!l.empty())
{
t=l.front();
if(t==i) { found=true; break; }
r.push(t);
l.pop();
}
if(!found) return false;
l.pop();
i+=1;
while(!l.empty() && !r.empty())
{
if(l.front()==i)
l.pop();
else if(r.top()==i)
r.pop();
else
{
found=false;
while(!l.empty())
{
t=l.front();
if(t==i) { found=true; break; }
r.push(t);
l.pop();
}
if(!found) return false;
l.pop();
}
i+=1;
}
return true;
}
void bfs(long start)
{
long i,next,u;
d[start]=0;
vis[start]=1;
q.push(start);
while(!q.empty())
{
u=q.front();
q.pop();
for(i=0;i<gr[u].size();i++)
{
next=gr[u][i];
if(!vis[next])
{
q.push(next);
vis[next]=1;
d[next]=d[u]+1;
}
}
}
}
long bfs(long start)
{
long i,u,next,count=0;
vis[start]=true;
q.push(start);
while(!q.empty())
{
count++;
u=q.front();
q.pop();
for(i=0; i<gr[u].size(); i++)
{
next=gr[u][i];
if(vis[next]==false)
{
q.push(next);
vis[next]=true;
}
}
}
return count;
}