#include #include #include #include #include #include #include #include #include using namespace std; typedef long long int llint; typedef int beet; #define ween tuple #define mp make_pair #define mt make_tuple #define pub push_back #define puf push_front #define pob pop_back #define pof pop_front #define izryt bool #define fir first #define sec second #define res resize #define ins insert #define era erase const llint mod=1000000007; const llint big=1e9+1e8; const llint red=0xE869120; const llint pro=1002001; //2n C n int main(void){ llint ans=1,n,i; cin>>n; for(i=1;i<=2*n;i++){ ans*=i;ans%=mod; } llint gy=mod-2; llint gen=1; for(i=1;i<=n;i++){gen*=2;gen%=mod;} while(gy>0){if(gy%2==1){ans*=gen;ans%=mod;}gen*=gen;gen%=mod;gy/=2;} cout<