import sys
from math import sqrt, pi, sin, factorial
inp = lambda : sys.stdin.readline()[:-1]
mii = lambda x = " " : [*map(int,inp().split(x))]
mfi = lambda x = " " : [*map(float,inp().split(x))]
ii = lambda : int(inp())
fi = lambda : float(inp())
n, s = mii()
l = [ii() for _ in range(n)]
crt = 0
for i in l[:-1]:
crt += i
if crt > s:
crt -= 1
crt += l[-1]
print(crt)