N=int(input())
S=list(input())

One=0
Nine=0
ans=0
for i in range(N):
    if S[i]=="9":
        if One>0:
            ans+=1
            One-=1
        else:
            Nine+=1
    elif S[i]=="1":
        if Nine>=2:
            ans+=1
            Nine-=2
        else:
            One+=1
    else:
        ans+=1
ans+=One//2
print(ans)

for i in range(2,991):
    if 991%i==0:
        print("991",i)