# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
# from collections import defaultdict
# con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N = int(input())
	Z = getlist()
	ans = str(Z[-1]) + "/" + str(Z[0])
	print(ans)

if __name__ == '__main__':
	main()