#include<bits/stdc++.h> using namespace std; int n; int a[100005],b[100005]; int main(){ cin>>n; int ans1,ans2; for(int i=1;i<=n;i++){ cin>>a[i]>>b[i]; ans1+=a[i]; ans2+=b[i]; } int min=b[1]; for(int i=1;i<=n;i++){ if(b[i]<min) min=b[i]; } int ans=ans1+min; cout<<ans; return 0; }