include<stdio.h>

define ll long long

define mod 1000000007

int main(){

ll n, s = 0, fib[1001];
scanf("%lld", &n);
fib[0] = 1, fib[1] = 0;
for (ll i = 2; i <= n; i++){
    fib[i] = (fib[i - 1] + fib[i - 2]) % mod;
    s = (s + fib[i]) % mod;
}
printf("%lld", s);

}