#include<bits/stdc++.h>
#define endl enjoy_codeforces
int main(){
    int n;std::cin>>n;
    int a=0,b=0;
    n--;
    while(n--){
        int x,y;std::cin>>x>>y;
        a+=x,b+=y;
    }
    std::cout<<std::min(a,b)+1<<'\n';
}