//http://contest-hunter.org:83/contest/0x10%E3%80%8C%E5%9F%BA%E6%9C%AC%E6%95%B0%E6%8D%AE%E7%BB%93%E6%9E%84%E3%80%8D%E4%BE%8B%E9%A2%98/1102%20%E7%81%AB%E8%BD%A6%E8%BF%9B%E5%87%BA%E6%A0%88%E9%97%AE%E9%A2%98 #include #include #include #include using namespace std; const int maxn=60005; int n,p[maxn*2],isp[maxn*2],res[1000005]={0,1},len=1,pcnt; inline void times(int x) { for(int i=1;i<=len;i++) res[i]*=x; len+=6; for(int i=1;i<=len;i++) { res[i+1]+=res[i]/10; res[i]%=10; } while(!res[len]) len--; } int main() { #ifdef local freopen("pro.in","r",stdin); #endif scanf("%d",&n); memset(isp,1,sizeof(isp)); isp[0]=isp[1]=0; for(int i=2;i<=n*2;i++) { if(isp[i]) p[pcnt++]=i; for(int j=0;j=1;i--) printf("%d",res[i]); puts(""); return 0; }