#include<bits/stdc++.h> using namespace std; int main(){ int n,a[100010],b[100010],c[100010],minb=0x3f3f3f3f; long long ans=0; cin>>n; for(int i=1;i<=n;i++){ cin>>a[i]>>b[i]; ans+=a[i]; minb=min(minb,b[i]); } cout<<ans+minb; return 0; }