533 B | 533 chars
import sys
from math import sqrt, pi, sin, factorial
inp = lambda : sys.stdin.readline()[:-1].strip()
mii = lambda x = " " : [*map(int,inp().split(x))]
mfi = lambda x = " " : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
p = print
def solve():
n = ii()
a = ii()
b = ii()
x = ii()
y = ii()
k = (n - b, n - a)
k2 = (x, y)
return max(0, min(k[1], k2[1]) - max(k[0], k2[0]) + 1)
if __name__ == "__main__":
tc = 1
for t in range(1, tc+1):
ret = solve()
p(ret)