#include "stdio.h"
#include "string.h"
#define MOD ((long long)1e9+7)
long long t,d[1210],dp[1210][1210],np[1210][1210],fac[1210];
long long countx;
long long c(int n,int k){
    if(k==0||k==n) return 1;
    if(np[n][k]!=-1) return np[n][k];
    return np[n][k]=(c(n-1,k)+c(n-1,k-1))%MOD;
}
long long p(int n,int k){
    return c(n,k)*fac[k]%MOD;
}
long long solve(long long n,long long k){
    //printf("call: %lld %lld\n",n,k);
    if(n>t) return 1;
    if(dp[n][k]!=-1) return dp[n][k];
    long long limit=n;
    for(long long i=n+1;d[i]>=d[i-1]&&i<n+k&&i<=t;i++) limit=i;
    long long countx=0;
    for(long long i=n;i<=limit;i++) countx+=(p(k,i-n+1)*solve(i+1,i-n+1)%MOD),countx%=MOD;
    return dp[n][k]=countx;
}
int main(){
    memset(np,-1,sizeof(np)),memset(dp,-1,sizeof(dp));
    scanf("%lld",&t);
    fac[1]=1;
    for(int i=2;i<=t;i++) fac[i]=fac[i-1]*i%MOD;
    for(long long i=1;i<=t;i++) scanf("%lld",&d[i]);
    long long limit=1;
    for(long long i=2;d[i]>=d[i-1]&&i<=t;i++) limit=i;
    for(long long i=1;i<=limit;i++) countx+=solve(i+1,i),countx%=MOD;//,printf("check: %lld\n",countx);
    printf("%lld",countx);
}