k = int(input())
a = []
for i in range(1,100001):
    a.append(1)
for i in range(1,100001):
    if(a[i] == 1):
        for j in range(i, 100001, i):
            a[j] = 0
b = []
for i in range(1,100001):
    if a[i] == 1:
        b.append(i)
print(b[k-1])