#include <iostream>
#include <map>

using namespace std;

const int N = 110;
map<int, int> sol;
int op[N];
int n;

int main(){
    cin >>n;
    int cnt = 0,cntij = 0;

    for(int i=1; i<=n; i++)
        cin >>op[i];

    for(int i=1; i<=n; i++){
        for(int j=i+1; j<=n; j++){
            //假设i j为狼
            cnt = 0;    //cnt为非狼说谎数
            cntij = 0;  //cntij为狼的说慌数

            //判断条件  失败continue
            for(int k=1; k<=n; k++){
                if(op[k] >0){
                    //判断是人
                    if(op[k] != i && op[k] != j){//真话 
                    }else{
                        if(k == i || k == j)
                            cntij ++;
                        else
                            cnt ++;
                    }
                }else{
                    //判断是狼
                    int l = ~op[k] + 1;
                    if(l == i || l == j){//真话
                    }else{
                        if(k == i || k == j)
                            cntij ++;
                        else
                            cnt ++;
                    }
                }
            }
            //成功map.insert
            if(cnt == 1 && cntij == 1)
                sol.insert({i,j});
        }
    }

    if(sol.size() == 0){
        cout <<"No Solution";
        return 0;     
    }
    auto i = sol.begin();
        cout <<i->first<<" "<<i->second<<endl;  
}