Code:zz
Thinking:zz kk
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//#pragma comment(linker, "/STACK:102400000,102400000") #include<iostream> #include<stdio.h> #include<stdlib.h> #include<string.h> #include<string> #include<math.h> #include<cmath> #include<time.h> #include<map> #include<set> #include<vector> #include<queue> #include<algorithm> #include<numeric> #include<stack> #include<bitset> #include<unordered_map> const int maxn = 0x3f3f3f3f; const double EI = 2.71828182845904523536028747135266249775724709369995957496696762772407663035354594571382178525166427; const double PI = 3.141592653589793238462643383279; using namespace std; long long p = 998244353; long long c[30] = {1,2,6,14,38,100,268,726,1974,5404,14852,40972,113388,314632, 875112,2439014,6810102,19045612,53341428,149589348}; int main(void) { //ios::sync_with_stdio(false); int n,i,j,k; long long ans; while(~scanf("%d",&n)) { printf("%lld\n",c[n - 1]); } return 0; }