#include <cstdio>
#include <cstring>

int p;
long long dp[19][10][2];

long long rec(int index, int remainder, bool hasThree){
    if(index == p){return remainder == 0 || hasThree;}
    
    auto& res = dp[index][remainder][hasThree];
    if(res != -1){return res;}

    res = 0;
    for(int i=0;i<=9;i++){
        res += rec(index+1, (remainder+i) % 3, hasThree || i == 3);
    }

    return res;
}

int main(){
    scanf("%d", &p);
    memset(dp, -1ll, sizeof(dp));
    printf("%lld\n", rec(0, 0, false) - 1);
}