#!/usr/bin/env python3

from operator import mul
from functools import reduce

def factorize(bound):
    sieve = [[] for i in range(bound)]
    for n in range(2, bound):
        if sieve[n] == []:
            sieve[n] = [n]
        for i in range(2, n+1):
            if i*n >= bound:
                break
            sieve[i*n] = sieve[i] + sieve[n]
    return sieve

def bin(row, col, fnums):
    num = [f for a in fnums[row-col+1:row+1] for f in a]
    den = [f for a in fnums[1:col+1] for f in a]
    for f in set(num):
        if num.count(f) - den.count(f) > 1:
            return 0
    return reduce(mul, num) // reduce(mul, den)


rn = 51
fnums = [[1] + i for i in factorize(rn)]
t = 0
dup = []
for row in range(2, rn):
    for col in range(1, row//2+1):
        n = bin(row, col, fnums)
        if n in dup:
            continue
        t += n
        dup.append(n)

print(t+1)