#include<bits/stdc++.h>
#define pb push_back
#define int long long
#define vi vector<int>
#define vvi vector<vector<int>>
#define pii pair<int, int>
#define vpii vector<pair<int, int>>
#define vc vector<char>
#define vb vector<bool>
#define mii map<int,int>
#define f0r(i,n) for(int i=0;i<n;i++)
#define FOR(i,k,n) for(int i=k;i<n;i++)
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define in(a) int a; cin>>a
#define in2(a,b) int a,b; cin>>a>>b
#define in3(a,b,c) int a,b,c; cin>>a>>b>>c
#define in4(a,b,c,d) int a,b,c,d; cin>>a>>b>>c>>d
#define vin(v,n); vi v(n); f0r(i,n){cin>>v[i];}
#define out(a) cout<<a<<'\n'
#define out2(a,b) cout<<a<<' '<<b<<'\n'
#define out3(a,b,c) cout<<a<<' '<<b<<' '<<c<<'\n'
#define out4(a,b,c,d) cout<<a<<' '<<b<<' '<<c<<' '<<d<<'\n'
#define vout(v) for(auto u : v){cout<<u<<' ';} cout<<'\n'
#define dout(a) cout<<a<<' '<<#a<<'\n'
#define dout2(a,b) cout<<a<<' '<<#a<<' '<<b<<' '<<#b<<'\n'
#define yn(x); if(x){cout<<"YES"<<'\n';}else{cout<<"NO"<<'\n';}
const int leg = 1e9 + 7;
const int mod = 998244353;
const int mxn = 5e6 + 5;
using namespace std;
signed main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
//ifstream cin(".in");
//ofstream cout(".out");
in(n);
vpii v;
f0r(i,n){
in2(a,b);
v.pb({a,b});
}
int s = 0;
f0r(i,n){
s += v[i].first * v[i].second;
}
vvi big(mxn);
vvi small(mxn);
vb vis(n, 0);
f0r(i,n){
big[v[i].first].pb(i);
small[v[i].second].pb(i);
}
vi ans;
FOR(l, 1, mxn){
if(s % l == 0 && l <= s/l){
int a = l;
int b = s/l;
f0r(i,n){
vis[i] = 0;
}
while(true){
bool ok = 0;
if(a < b)swap(a,b);
if(a < mxn){
for(auto u : big[a]){
if(!vis[u]){
vis[u] = 1;
ok = 1;
b -= v[u].second;
}
}
}
if(ok)continue;
for(auto u : small[b]){
if(!vis[u]){
vis[u] = 1;
ok = 1;
a -= v[u].first;
}
}
if(ok)continue;
for(auto u : big[b]){
if(!vis[u]){
vis[u] = 1;
ok = 1;
a -= v[u].second;
}
}
if(!ok)break;
}
if(a * b == 0)ans.pb(l);
}
}
out(ans.size());
f0r(i, ans.size())out(ans[i]);
}
