solveit

#include<bits/stdc++.h>
using namespace std;

set<int> s;

int main() {
//set + lower_bound
   int n, q; scanf("%d %d", &n, &q);

   while(q--){

      int k, y; scanf("%d %d", &k, &y);

      if(k == 1){
         s.insert(y);
      }
      else{
         auto resp = s.lower_bound(y);
         if(resp != s.end()){
            printf("%d\n", *resp);

         }
         else{
            printf("-1\n");
         }
      }
   }

}