Commit 5a48ec4

#include<bits/stdc++.h>

using namespace std;

#define MOD 9901

int dp[100001][3];

int main(){

ios_base::sync_with_stdio(0), cin.tie(NULL), cout.tie(NULL);

int n;

cin>>n;

dp[1][0] = 1;

dp[1][1] = 1;

dp[1][2] = 1;

for(int i = 2; i <= n; i++){

dp[i][0] = (dp[i-1][1] + dp[i-1][2] + dp[i-1][0])%MOD;

dp[i][1] = (dp[i-1][0] + dp[i-1][2])%MOD;

dp[i][2] = (dp[i-1][0] + dp[i-1][1])%MOD;

}

cout<<(dp[n][0]+dp[n][1]+dp[n][2])%MOD<<"\n";

return 0;

}