Happy Birthday UVa 12002

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>

using namespace std;
#define forn(i,n) for(int i=0;i<(int)(n);i++)
#define forsn(i,s,n) for(int i=(int)(s);i<(int)(n);i++)

//dp[i][j] cantidad de platos que puedo agarrar con i el plato de la base y j el plato del tope.
int n,dp[512][512], dish[512];

int main(){
        #ifdef JUAMPI
            freopen("12002.in","r",stdin);
        #endif

        for(scanf("%d",&n);n != 0; scanf("%d",&n)){
            dish[0] = 100000; dish[1] = 0;
            forsn(i,2,n+2) scanf("%d",&dish[i]);

            memset(dp,0,sizeof(dp));
            forsn(i,2,n+2) dp[i][i] = 1;
            forsn(i,2,n+2){
                forn(j,i){
                    forn(k,i){
                        if(dish[j] < dish[k]) continue;

                        if(dish[i] >= dish[j] && dp[i][k] < dp[j][k]+1){
                            dp[i][k] = dp[j][k]+1;
                        }
                        if(dish[i] <= dish[k] && dp[j][i] < dp[j][k]+1){
                            dp[j][i] = dp[j][k]+1;
                        }
                    }
                }
            }

            int res = 0;
            forn(i,n+2)
            forn(j,n+2)
                if(res < dp[i][j]) res = dp[i][j];

            printf("%d\n",res);
        }

        return 0;
}