// compile: g++ -o data data.cpp -O3 -std=gnu++20 -Wall -Wextra -Wshadow -D_GLIBCXX_ASSERTIONS -ggdb3 -fmax-errors=2 -DLOCAL
// run: ./data < data.in
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#ifdef LOCAL
#include <debug/codeforces.h>
#define debug(x...) {_variables(#x);_print(x);}
#else
#define debug(x...)
#endif
template<typename...Args> void print_(Args...args){((cout<<args<<" "),...)<<endl;}
#define rep(i,a,b) for(int i=(a);i<(b);++i)
#define sz(v) ((int)(v).size())
#define print(...) print_(__VA_ARGS__);
#define INTINF (int)(9223372036854775807)
#define int long long
#define MAXN 200010
int n;
int dp[MAXN][11];
int32_t main() {
ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
cin >> n;
memset(dp, 0, sizeof(dp));
dp[0][0] = 1;
for (int i = 1; i <= n; ++i) {
for (int bit = 1; bit < 10; ++bit) {
if (i - bit < 0) continue;
for (int j = 1; j < 10; ++j) {
if (j == bit) continue;
dp[i][bit] += dp[i-bit][j];
}
}
}
int sum = 0;
for (int i = 0; i < 10; ++i) sum += dp[n][i];
for (int i = 1; i <= 4; ++i) debug(dp[i][0], dp[i][1], dp[i][2], dp[i][3], dp[i][4])
// cout << sum << endl;
return 0;
}
No Comments