import numpy as np

def repeating_numbers():                            
    n=np.random.randint(2,16,size=1)           # making "n" between 2-15,since the number of people rolling the die is 2-15
    die_roll =np.random.randint(1,21,size=n)     # number on die with n amount of times 
    unique_values=[]
    for value in die_roll:
        if value not in unique_values:
            unique_values.append(value)
    if len(unique_values) ==n:                  # if total number is less than n then it means that at least 2 people rolled the same number
        return 0                                # if n is exactly n than it mean each people rolled a different number 
    else: 
        return 1
        

sum([repeating_numbers() for i in range(1000)])/1000 # calculating the probabilty by adding up all the ones in the trials and divide it by the                                                        total amount of trials (in this case 1000 trials)