#include <bits/stdc++.h> using namespace std; #define repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++) #define rep(i,n) repl(i,0,n) #define mp(a,b) make_pair((a),(b)) #define pb(a) push_back((a)) #define all(x) (x).begin(),(x).end() #define uniq(x) sort(all(x)),(x).erase(unique(all(x)),end(x)) #define fi first #define se second #define dbg(x) cout<<#x" = "<<((x))<<endl template<class T,class U> ostream& operator<<(ostream& o, const pair<T,U> &p){o<<"("<<p.fi<<","<<p.se<<")";return o;} template<class T> ostream& operator<<(ostream& o, const vector<T> &v){o<<"[";for(T t:v){o<<t<<",";}o<<"]";return o;} #define INF 2147483600 #define long long long int main(){ rep(i,10){ int d; cin>>d; if(d-1!=i){ cout<<i+1<<endl; return 0; } } return 0; }