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 = 0;
        boolean flag = false;
        int sum = Arrays.stream(h).sum();

        while (sum != 0) {
            for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            }
            flag = false;
        }

        System.out.print(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 = 0;
        boolean flag = false;
        int sum = Arrays.stream(h).sum();

        while (sum != 0) {
            for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            }
            flag = false;
        }

        System.out.print(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 = 0;
        boolean flag = false;
        int sum = Arrays.stream(h).sum();

        while (sum != 0) {
            for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            }
            flag = false;
        }

        System.out.print(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 = 0;
        boolean flag = false;
        int sum = Arrays.stream(h).sum();

        while (sum != 0) {
            for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            }
            flag = false;
        }

        System.out.print(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 = 0; count 0 boolean flag = false; flag false int sum = Arrays.stream(h).sum(); sum Arrays.stream(h).sum() Arrays.stream(h).sum Arrays.stream(h) Arrays.stream Arrays h while (sum != 0) {
            for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            }
            flag = false;
        } sum != 0 sum 0 {
            for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            }
            flag = false;
        } for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            } {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            } if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                } h[i] > 0 h[i] h i 0 {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } if (!flag) {
                        flag = true;
                        count++;
                    } !flag flag {
                        flag = true;
                        count++;
                    } flag = true flag true count++ count h[i]-- h[i] h i sum-- sum {
                    flag = false;
                } flag = false flag false flag = false flag false System.out.print(count) System.out.print 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 = 0;
        boolean flag = false;
        int sum = Arrays.stream(h).sum();

        while (sum != 0) {
            for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            }
            flag = false;
        }

        System.out.print(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 = 0;
        boolean flag = false;
        int sum = Arrays.stream(h).sum();

        while (sum != 0) {
            for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            }
            flag = false;
        }

        System.out.print(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 = 0;
        boolean flag = false;
        int sum = Arrays.stream(h).sum();

        while (sum != 0) {
            for (int i = 0; i < n; i++) {
                if (h[i] > 0) {
                    if (!flag) {
                        flag = true;
                        count++;
                    }
                    h[i]--;
                    sum--;
                } else {
                    flag = false;
                }
            }
            flag = false;
        }

        System.out.print(count);
    }
}
