#include<cstdio>#include<cstring>#include<algorithm>using namespace std;typedef long long ll;ll c[30][30];int n;ll dfs(char s1[],char s2[]){ ll ans=1; if(s1[0]==s2[0]) return 1ll; int i,j,k,cnt=0,len=strlen(s1); for(i=1,j=0;i<len;) { k=1; while(s1[i]!=s2[j]) j++,k++; cnt++; char t1[30],t2[30]; strncpy(t1,s1+i,k); strncpy(t2,s2+j-k+1,k); t1[k]=t2[k]=' '; ans*=dfs(t1,t2); i+=k; j++; } return ans*c[n][cnt];}int main(){ c[0][0]=1; for(int i=1;i<=20;i++) { c[i][0]=c[i][i]=1; for(int j=1;j<i;j++) { c[i][j]=c[i-1][j]+c[i-1][j-1]; } } while(scanf("%d",&n),n) { char s1[30],s2[30]; scanf("%s%s",s1,s2); printf("%lldn",dfs(s1,s2)); } return 0;}
