#include<bits/stdc++.h>
#define pb push_back
#define F first
#define S second
#define str string
#define ll long long
#define ull unsigned ll
#define ld long double
#define pll pair<ll,ll>
#define plll pair<ll,pll>
#define pllll pair<pll,pll>
#define pii pair<int,int>
#define vl vector<ll>
#define vll vector<pll>
#define vlll vector<plll>
#define vllll vector<pllll>
#define vi vector<int>
#define vii vector<pii>
#define sz(x) (ll)(x).size()
#define fr front()
#define tp top()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define ins insert
#define m_p make_pair
#pragma GCC target( "sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("Ofast,unroll-loops,fast-math,O3")
using namespace std;
const ld pi=acos(-1.0);
const ll e5=1e5, e6=1e6, e9=1e9;
const ll inf=1e18;
const ll mod=1e9+7;
const ll MOD=106710087877475399;
const ll N=1e3+10;
const ll M=2e5+10;
const ld eps=1e-9;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll bpm(ll x,ll y,ll m){if(y==0)return 1%m;ll p=bpm(x,y/2,m);
if(y%2==0)return p*p%m;else return p*p%m*x%m;}
ll bp(ll x,ll y){if(y==0)return 1;ll p=bp(x,y/2);
if(y%2==0)return p*p;else return p*p*x;}
ll n,a[N],b[N];
void solve(){
cin>>n;
ll s=0;
for(ll i=1;i<=n;i++) cin>>a[i]>>b[i], s+=a[i]*b[i];
vl ans;
if(s%a[n]==0){
ll x=a[n], y=s/a[n];
for(ll i=n;i>=1;i--){
if(x<y) swap(x,y);
if(i==1){
if(x==a[i]&&y==b[i]) ans.pb(min(a[n],s/a[n]));
}else{
if(x==a[i]) y-=b[i];
else if(x==b[i]) y-=a[i];
else if(y==a[i]) x-=b[i];
else if(y==b[i]) x-=a[i];
else break;
}
}
}
if(s%b[n]==0){
ll x=b[n], y=s/b[n];
for(ll i=n;i>=1;i--){
if(x<y) swap(x,y);
if(i==1){
if(x==a[i]&&y==b[i]) ans.pb(min(b[n],s/b[n]));
}else{
if(x==a[i]) y-=b[i];
else if(x==b[i]) y-=a[i];
else if(y==a[i]) x-=b[i];
else if(y==b[i]) x-=a[i];
else break;
}
}
}
sort(all(ans));
cout<<sz(ans)<<'\n';
for(ll x:ans) cout<<x<<'\n';
return;
}
int main(/*Aldk*/){
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
// freopen("hyper.in", "r", stdin);
// freopen("hyper.out ", "w", stdout);
//cout<<setprecision(6)<<fixed;
int test=1;
// cin>>test;
for(int i=1;i<=test;i++){
solve();
cout<<'\n';
}
return 0;
}
