AF-Fump: for

# include <bits/stdc++.h>
# define  se second
# define fr first
# define MOD 1000000007
# define ll long long
# define pb push_back
using namespace std;
int main()
{
    ll n , i ,ans = 1000000 , x ,y ;
    cin>> n;
    for(i = 1; i <= n; i ++){
        cin>> x>>y ;
        ans = min(ans , y - x);
    }
    cout << ans<<'\n';
}