This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define run ios_base::sync_with_stdio(false);cin.tie(0);
#define ll long long
#define pll pair<ll, ll>
#define ull unsigned ll
#define ld double
#define endl "\n"
#define pb push_back
#define fi first
#define se second
#define pi acos(-1)
#define N 100007
#define minimum -9223372036854775807
#define maximum -minimum
#define mod 1000007
using namespace std;
using namespace __gnu_pbds;
template <class t>
using ordered_set=tree<t, null_type,less_equal<t>, rb_tree_tag,tree_order_statistics_node_update>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll gcd(ll a, ll b)
{
if(b==0)
return a;
return gcd(b, a%b);
}
ll lcm(ll a, ll b)
{
return a/gcd(a, b)*b;
}
bool isprime(ll n)
{
if(n==1)
return 0;
for(ll i=2; i*i<=n; i++)
{
if(n%i==0)
return 0;
}
return 1;
}
ll binpow(ll a, ll b)
{
a%=mod;
ll res=1;
while(b>0)
{
if(b%2==1)
res=(res*a)%mod;
a=(a*a)%mod;
b/=2;
}
return res;
}
ll dp[N];
int main()
{
run;
ll n;
cin>>n;
ll a[n+1];
for(ll i=1; i<=n; i++)
{
cin>>a[i];
}
dp[1]=1;
for(ll i=2; i<=n; i++)
{
for(ll j=1; j<i; j++)
{
dp[i]=(dp[i]+dp[j])%mod;
}
dp[i]=(dp[i]+dp[i-1])%mod;
}
cout<<dp[n]%mod<<endl;
}
/*
1 - 1
2 - 2
3 - 5
4 - 13
5 - 34
1
1 1
2
1 1 1
1 2 2
3
1 1 1 1
1 1 2 2
1 2 1 3
1 2 2 4
1 2 3 5
4
1 1 1 1 1
1 1 1 2 2
1 1 2 1 3
1 1 2 2 4
1 1 2 3 5
1 2 1 1 6
1 2 1 2 7
1 2 2 1 8
1 2 2 2 9
1 2 2 3 10
1 2 3 2 11
1 2 3 3 12
1 2 3 4 13
5
1 1 1 1 1 1
1 1 1 1 2 2
1 1 1 2 1 3
1 1 1 2 2 4
1 1 1 2 3 5
1 1 2 1 1 6
1 1 2 1 2 7
1 1 2 2 1 8
1 1 2 2 2 9
1 1 2 2 3 10
1 1 2 3 2 11
1 1 2 3 3 12
1 1 2 3 4 13
1 2 1 1 1 14
1 2 1 1 2 15
1 2 1 2 1 16
1 2 1 2 2 17
1 2 1 2 3 18
1 2 2 1 1 19
1 2 2 1 2 20
1 2 2 2 1 21
1 2 2 2 2 22
1 2 2 2 3 23
1 2 2 3 2 24
1 2 2 3 3 25
1 2 2 3 4 26
1 2 3 2 1 27
1 2 3 2 2 28
1 2 3 2 3 29
1 2 3 3 2 30
1 2 3 3 3 31
1 2 3 3 4 32
1 2 3 4 4 33
1 2 3 4 5 34
*/
// By Xanlar
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