import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		// 入力
		int N = sc.nextInt();
		
		int[] h = new int[N];
		for (int i = 0; i < N; i++) {
			h[i] = sc.nextInt();
		}
		
		// 入力チェック
		/*
		if (error) {
			System.out.println("無効な入力値です");
			return;
		}
		*/
		// 答えを出力
		int ans = 0;
		ans += h[0];
		for (int i = 1; i < N; i++) {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		}
		System.out.println(ans);
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		// 入力
		int N = sc.nextInt();
		
		int[] h = new int[N];
		for (int i = 0; i < N; i++) {
			h[i] = sc.nextInt();
		}
		
		// 入力チェック
		/*
		if (error) {
			System.out.println("無効な入力値です");
			return;
		}
		*/
		// 答えを出力
		int ans = 0;
		ans += h[0];
		for (int i = 1; i < N; i++) {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		}
		System.out.println(ans);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		// 入力
		int N = sc.nextInt();
		
		int[] h = new int[N];
		for (int i = 0; i < N; i++) {
			h[i] = sc.nextInt();
		}
		
		// 入力チェック
		/*
		if (error) {
			System.out.println("無効な入力値です");
			return;
		}
		*/
		// 答えを出力
		int ans = 0;
		ans += h[0];
		for (int i = 1; i < N; i++) {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		}
		System.out.println(ans);
	} main {
		Scanner sc = new Scanner(System.in);
		// 入力
		int N = sc.nextInt();
		
		int[] h = new int[N];
		for (int i = 0; i < N; i++) {
			h[i] = sc.nextInt();
		}
		
		// 入力チェック
		/*
		if (error) {
			System.out.println("無効な入力値です");
			return;
		}
		*/
		// 答えを出力
		int ans = 0;
		ans += h[0];
		for (int i = 1; i < N; i++) {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		}
		System.out.println(ans);
	} 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 ans = 0; ans 0 ans += h[0] ans h[0] h 0 for (int i = 1; i < N; i++) {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		} int i = 1; int i = 1; i 1 i < N i N i++ i++ i {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		} {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		} if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			} h[i] > h[i-1] h[i] h i h[i-1] h i-1 i 1 {
				ans += h[i] - h[i-1];
			} ans += h[i] - h[i-1] ans h[i] - h[i-1] h[i] h i h[i-1] h i-1 i 1 System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		// 入力
		int N = sc.nextInt();
		
		int[] h = new int[N];
		for (int i = 0; i < N; i++) {
			h[i] = sc.nextInt();
		}
		
		// 入力チェック
		/*
		if (error) {
			System.out.println("無効な入力値です");
			return;
		}
		*/
		// 答えを出力
		int ans = 0;
		ans += h[0];
		for (int i = 1; i < N; i++) {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		}
		System.out.println(ans);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		// 入力
		int N = sc.nextInt();
		
		int[] h = new int[N];
		for (int i = 0; i < N; i++) {
			h[i] = sc.nextInt();
		}
		
		// 入力チェック
		/*
		if (error) {
			System.out.println("無効な入力値です");
			return;
		}
		*/
		// 答えを出力
		int ans = 0;
		ans += h[0];
		for (int i = 1; i < N; i++) {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		}
		System.out.println(ans);
	}
} Main
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		// 入力
		int N = sc.nextInt();
		
		int[] h = new int[N];
		for (int i = 0; i < N; i++) {
			h[i] = sc.nextInt();
		}
		
		// 入力チェック
		/*
		if (error) {
			System.out.println("無効な入力値です");
			return;
		}
		*/
		// 答えを出力
		int ans = 0;
		ans += h[0];
		for (int i = 1; i < N; i++) {
			if(h[i] > h[i-1]) {
				ans += h[i] - h[i-1];
			}
		}
		System.out.println(ans);
	}
}
