#include <cstdio>
#include <cmath>
#define MOD 1000000007
int cnt, n;
long long ans[2] = {1};

void hanoi(int n, char st, char tp, char ed)
{
    if( cnt > 100 ) return;
    if( n > 0 )
    {
        if( cnt < 100 ) hanoi(n-1, st, tp, ed);
        if( cnt < 100 ) printf("%d : %c->%c\n", n, st, tp), cnt++;
        if( cnt < 100 ) hanoi(n-1, ed, tp, st);
        if( cnt < 100 ) printf("%d : %c->%c\n", n, tp, ed), cnt++;
        if( cnt < 100 ) hanoi(n-1, st, tp, ed);
    }
}

int main()
{
    for(int p = 1 ; p <= 30 ; p++ )
    {
        cnt = 0;
        char in[110], out[110];
        sprintf(in, ".%d.in", p);
        sprintf(out, ".%d.out", p);
        freopen(in, "r", stdin);
        freopen(out, "w", stdout);
    scanf("%d", &n);
    hanoi((n>5?5:n), 'A', 'C', 'B');
    for(int i = 1 ; i <= n ; i++ )
        ans[i%2] = ans[(i-1)%2]*3, ans[i%2]%=MOD;
    printf("%lld\n", (ans[n%2]-1));
    }
}