//#Finding the Second Largest Element:
//You are given a sequence of integers as input, terminated by -1. (That is, the input integers may be positive, negative or 0. -1 in the input signals the end of the input.)
//-1 is not considered as part of the input.
//Find the second largest number in the input. You should not use arrays.
//Sample Test Cases
//Test Case 1
//Input
//-840 -288 -261 -337 -335 488 -1
//Output
//-261

public class Solution {

    public static void main(String[] args) {
        int max=-9999999;
        int secMax=-9999998;
        Scanner in = new Scanner(System.in);
        int n=0;
        while((n=in.nextInt())!=-1){
            if(n>max){
                secMax = max;
                max = n;
            }
        }
        if(secMax!=-9999999){
            System.out.println(secMax);
        }
    }
}