import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] h = new int[N + 1];
    for (int i = 1; i <= N; i++) {
      h[i] = sc.nextInt();
    }
    int ans = 0;
    for (int i = 1; i <= N; i++) {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    }
    System.out.println(ans);
  }
} import java.util.Scanner; Scanner 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 + 1];
    for (int i = 1; i <= N; i++) {
      h[i] = sc.nextInt();
    }
    int ans = 0;
    for (int i = 1; i <= N; i++) {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    }
    System.out.println(ans);
  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] h = new int[N + 1];
    for (int i = 1; i <= N; i++) {
      h[i] = sc.nextInt();
    }
    int ans = 0;
    for (int i = 1; i <= N; i++) {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    }
    System.out.println(ans);
  } main {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] h = new int[N + 1];
    for (int i = 1; i <= N; i++) {
      h[i] = sc.nextInt();
    }
    int ans = 0;
    for (int i = 1; i <= N; i++) {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    }
    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 + 1]; h new int[N + 1] N + 1 N 1 for (int i = 1; i <= N; i++) {
      h[i] = sc.nextInt();
    } int i = 1; int i = 1; i 1 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 for (int i = 1; i <= N; i++) {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    } int i = 1; int i = 1; i 1 i <= N i N i++ i++ i {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    } {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    } int d = h[i] - h[i - 1]; d h[i] - h[i - 1] h[i] h i h[i - 1] h i - 1 i 1 if (d > 0) {
        ans += d;
      } d > 0 d 0 {
        ans += d;
      } ans += d ans d 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);
    int N = sc.nextInt();
    int[] h = new int[N + 1];
    for (int i = 1; i <= N; i++) {
      h[i] = sc.nextInt();
    }
    int ans = 0;
    for (int i = 1; i <= N; i++) {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    }
    System.out.println(ans);
  }
} public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] h = new int[N + 1];
    for (int i = 1; i <= N; i++) {
      h[i] = sc.nextInt();
    }
    int ans = 0;
    for (int i = 1; i <= N; i++) {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    }
    System.out.println(ans);
  }
} Main
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int[] h = new int[N + 1];
    for (int i = 1; i <= N; i++) {
      h[i] = sc.nextInt();
    }
    int ans = 0;
    for (int i = 1; i <= N; i++) {
      int d = h[i] - h[i - 1];
      if (d > 0) {
        ans += d;
      }
    }
    System.out.println(ans);
  }
}
