#include #include #include #include #include #include using namespace std; typedef long long LL; const LL mod=1e9+7; LL read(){ char ch=getchar(); while((ch<'0'||ch>'9')&&ch!='-') ch=getchar(); LL x,tag; if(ch=='-') x=0,tag=-1; else x=ch-'0',tag=1; ch=getchar(); while(ch>='0'&&ch<='9') x=x*10+ch-'0',ch=getchar(); return x*tag; } void writeln(LL x){ if(!x) putchar('0'); else{ if(x<0) putchar('-'),x=abs(x); LL ch[50],l=0; while(x) ch[l++]=x%10,x/=10; while(l) putchar(ch[--l]+'0'); } putchar('\n'); } const int maxn=2010; LL dp[maxn][4]; void work(){ int n=read(); writeln((dp[n][1]+dp[n][2]+dp[n][3])%mod); } int main(){ memset(dp,0,sizeof(dp)); dp[1][1]=26; for(int i=1; i