How to get user input in Java Nested Loops?

I am posting the full code only for contextual purposes. The issue I am having lies in the portion highlighted in the snippet below the full code.

import java.util.Scanner;
public class GradeAvg {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        int numStudents=0;
        int Males=0;
        int Females=0;
        int maleAvg=0;
        int femaleAvg=0;

        String Gender="";

        System.out.println("How many students?");
        numStudents=input.nextInt();

        for (int n=1; n <= numStudents; n++) {

         System.out.println("Is student "+ n +" male or female (M/F)?");
            Gender=input.nextLine();
            input.nextLine();


            if (Gender.equalsIgnoreCase("M")) {
                for (int malenum=n; malenum <= numStudents; Males++); {
                    System.out.println("What is student "+ n +"'s average?");
                    maleAvg=input.nextInt();
                    Males++;
            }
            }
            else if (Gender.equalsIgnoreCase("F")) {

                for (int femalenum=n; femalenum <= numStudents; Females++) {
                    System.out.println("What is student "+ n +"'s average?");
                    femaleAvg=input.nextInt();
                    Females++;
                }
            }

            maleAvg=numStudents/maleAvg;
            femaleAvg=numStudents/femaleAvg;
        }
        System.out.println("The " + Males +" male students average is: " + maleAvg);
        System.out.println("The " + Females +" female students average is: " + femaleAvg);


    }

}

Snippet:

System.out.println("How many students?");
numStudents=input.nextInt();

for (int n=1; n <= numStudents; n++) {

    System.out.println("Is student "+ n +" male or female (M/F)?");
    Gender=input.nextLine();
    input.nextLine();


    if (Gender.equalsIgnoreCase("M")) {
        for (int malenum=n; malenum <= numStudents; Males++); {
            System.out.println("What is student "+ n +"'s average?");
            maleAvg=input.nextInt();
            Males++;
        }
    }
    else if (Gender.equalsIgnoreCase("F")) {

        for (int femalenum=n; femalenum <= numStudents; Females++) {
            System.out.println("What is student "+ n +"'s average?");
            femaleAvg=input.nextInt();
            Females++;
        }
    }

When the full code is ran, I am prompted with the question "How many students?" This is correct, and I enter and integer such as "5". I then am prompted with the question "Is student 1 male or female (M/F)?" to which i reply "M".

It then (for some unknown reason) skips over the rest of the loop, and returns back to the question "Is student 2 male or female (M/F)?". I am not sure why this is happening, and I do not need the complete answer to this code as it is a homework problem. I simply need the explanation as to why my loop is working improperly, and how to get the prompts to pop up in the if statements in the loop. I really appreciate any and all help from everyone who chooses to comment.