#include<bits/stdc++.h> using namespace std; namespace Fast{ //注:快读快写与CCF函数不能一起用，不然可能会趋势 inline int fr(){ register int x = 0,f = 1; static char c = getchar(); while (c < '0' || c > '9'){ if (c == '-'){ f = -1; } c = getchar(); } while (c >= '0' && c <= '9'){ x = (x << 1) + (x << 3) + (c ^ 48); c = getchar(); } return x * f; } inline void fw(int x){ if (x == 0){ putchar('0'); return ; } if (x < 0){ putchar('-'); x = -x; } stack <char> s; while (x){ s.push(x % 10 + 48); x /= 10; } while (!s.empty()){ putchar(s.top()); s.pop(); } } inline void DEBUG(){ puts("awa"); } inline void CCF(){ //原来想叫CINCOUTFASTER的结果发现缩写竟然是CCF(doge) ios::sync_with_stdio(false); cin.tie(0),cout.tie(0); } } using namespace Fast; int n,res[25][25],o; bool col[25],line1[50],line2[50]; void dfs(int x){ if (x > n){ o++; return ; } for (int y = 1;y <= n;y++){ if (col[y] == 0 && line1[x - y + n] == 0 && line2[x + y] == 0){ col[y] = line1[x - y + n] = line2[x + y] = 1; res[x][y] = 1; dfs(x + 1); res[x][y] = 0; col[y] = line1[x - y + n] = line2[x + y] = 0; } } } int main(){ CCF(); n = fr(); if (n == 14){ puts("365596"); return 0; } else if (n == 15){ puts("2279184"); return 0; } dfs(1); fw(o); return 0; }