import java.util.*;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] h = new int[n];
        for (int i = 0; i < n; i++) {
            h[i] = sc.nextInt();
        }
        
        int count = h[0];
        for (int i = 1; i < n; i++) {
            count += Math.max(h[i] - h[i-1], 0);
        }
        System.out.println(count);
    }
}
 import java.util.*; util.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] h = new int[n];
        for (int i = 0; i < n; i++) {
            h[i] = sc.nextInt();
        }
        
        int count = h[0];
        for (int i = 1; i < n; i++) {
            count += Math.max(h[i] - h[i-1], 0);
        }
        System.out.println(count);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] h = new int[n];
        for (int i = 0; i < n; i++) {
            h[i] = sc.nextInt();
        }
        
        int count = h[0];
        for (int i = 1; i < n; i++) {
            count += Math.max(h[i] - h[i-1], 0);
        }
        System.out.println(count);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] h = new int[n];
        for (int i = 0; i < n; i++) {
            h[i] = sc.nextInt();
        }
        
        int count = h[0];
        for (int i = 1; i < n; i++) {
            count += Math.max(h[i] - h[i-1], 0);
        }
        System.out.println(count);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int[] h = new int[n]; h new int[n] n for (int i = 0; i < n; i++) {
            h[i] = sc.nextInt();
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            h[i] = sc.nextInt();
        } {
            h[i] = sc.nextInt();
        } h[i] = sc.nextInt() h[i] h i sc.nextInt() sc.nextInt sc int count = h[0]; count h[0] h 0 for (int i = 1; i < n; i++) {
            count += Math.max(h[i] - h[i-1], 0);
        } int i = 1; int i = 1; i 1 i < n i n i++ i++ i {
            count += Math.max(h[i] - h[i-1], 0);
        } {
            count += Math.max(h[i] - h[i-1], 0);
        } count += Math.max(h[i] - h[i-1], 0) count Math.max(h[i] - h[i-1], 0) Math.max Math h[i] - h[i-1] h[i] h i h[i-1] h i-1 i 1 0 System.out.println(count) System.out.println System.out System System.out count String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] h = new int[n];
        for (int i = 0; i < n; i++) {
            h[i] = sc.nextInt();
        }
        
        int count = h[0];
        for (int i = 1; i < n; i++) {
            count += Math.max(h[i] - h[i-1], 0);
        }
        System.out.println(count);
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] h = new int[n];
        for (int i = 0; i < n; i++) {
            h[i] = sc.nextInt();
        }
        
        int count = h[0];
        for (int i = 1; i < n; i++) {
            count += Math.max(h[i] - h[i-1], 0);
        }
        System.out.println(count);
    }
} Main
import java.util.*;
 
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] h = new int[n];
        for (int i = 0; i < n; i++) {
            h[i] = sc.nextInt();
        }
        
        int count = h[0];
        for (int i = 1; i < n; i++) {
            count += Math.max(h[i] - h[i-1], 0);
        }
        System.out.println(count);
    }
}

