#include <stdio.h>

int main(void) {
	long long int n, a[100001][3] = {0};
	long long int i;
	scanf("%lld", &n);
	a[1][0] = 1;
	for(i = 2;i <= n;i++){
		a[i][0] = a[i - 1][2] % 1000000007;
		a[i][1] = a[i - 1][0] % 1000000007;
		a[i][2] = (a[i - 1][0] + a[i - 1][1]) % 1000000007;
	}
	//for(i = 1;i <= n;i++){
	//	printf("%lld:%lld\n", i, (a[i][0] + a[i][1] + a[i][2]) % 1000000007);
	//}
	printf("%lld\n", (a[n][0] + a[n][1] + a[n][2]) % 1000000007);
	
	return 0;
}