Problem:
 Score : 200 points    Problem Statement Takahashi has N days of summer vacation.  His teacher gave him M summer assignments. It will take A_i days for him to do the i -th assignment.  He cannot do multiple assignments on the same day, or hang out on a day he does an assignment.  What is the maximum number of days Takahashi can hang out during the vacation if he finishes all the assignments during this vacation?  If Takahashi cannot finish all the assignments during the vacation, print -1 instead.      Constraints  1 \leq N \leq 10^6  1 \leq M \leq 10^4  1 \leq A_i \leq 10^4         Input Input is given from Standard Input in the following format:  N  M  A_1  ...  A_M       Output Print the maximum number of days Takahashi can hang out during the vacation, or -1 .        Sample Input 1 41 2
5 6      Sample Output 1 30  For example, he can do the first assignment on the first 5 days, hang out on the next 30 days, and do the second assignment on the last 6 days of the vacation. In this way, he can safely spend 30 days hanging out.       Sample Input 2 10 2
5 6      Sample Output 2 -1  He cannot finish his assignments.       Sample Input 3 11 2
5 6      Sample Output 3 0  He can finish his assignments, but he will have no time to hang out.       Sample Input 4 314 15
9 26 5 35 8 9 79 3 23 8 46 2 6 43 3      Sample Output 4 9

Solution (Python):
n,m = map(int,input().split())
Ai = list(map(int,input().split()))
print(n - sum(Ai) if n - sum(Ai) >= 0 else -1)

Solution (Python):
n,m = map(int, input().split())
l = list(map(int, input().split()))
a = sum(l)

if a > n:
    print('-1')
else:
    print(n - a)

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))
print(max(N - sum(A), -1))

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
print(max(-1, n-sum(a)))

Solution (Python):
N, M = map(int, input().split())
A = [int(x) for x in input().split()]

sm = sum(A)

print(N - sm if N >= sm else -1)

Solution (Python):
def main():
    nm = [int(_x) for _x in input().split()]
    n = nm[0]
    m = nm[1]
    a = [int(_x) for _x in input().split()]
    result = n - sum(a)
    if result < 0:
        print(-1)
    else:
        print(result)


main()

Solution (Python):


n,m = map(int,input().split())
a = list(map(int,input().split()))

days = sum(a)

if days > n:
    print(-1)
else:
    print(n-days)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
print(max(n-sum(a), -1))

Solution (Python):
n,m = map(int,input().split())
a = list(map(int,input().split()))

result = n-sum(a)

if result >= 0 :
  print(result)
else :
  print(-1)

Solution (Python):
n,m=map(int,input().split())
a=list(map(int,input().split()))

h=sum(a)

if n<h:
  print('-1')
else:
  print(n-h)

Solution (Python):
N,M = map(int,input().split())

sumlist =list(map(int,input().split()))

if N-sum(sumlist)>=0:
  print (N-sum(sumlist))
else :
  print (-1)

Solution (Python):
N,M=map(int,input().split())
A=list(map(int,input().split()))
print(max(N-sum(A),-1))

Solution (Python):
N,M=map(int,input().split())
A=list(map(int,input().split()))
B=sum(A)

if N>=B:
    print(N-B)
else:
    print(-1)

Solution (Python):


N, M = map(int, input().split())
A = list(map(int, input().split()))
print(N-sum(A)) if N - sum(A) >= 0 else print(-1)

Solution (Python):
a,b=input().split()
a=int(a)
b=int(b)
c=list(map(int,input().split()))
if sum(c)<=a:
  print(a-sum(c))
else:
  print(-1)

Solution (Python):
def main():
    N, M = map(int, input().split())
    A = list(map(int, input().split()))

    A_day = sum(A)
    hangout = N - A_day

    print(hangout) if hangout >= 0 else print(-1)


if __name__ == '__main__':
    main()

Solution (Python):
n,m=map(int,input().split())
a =map(int,input().split())
x = sum(a)
if x > n:
    print('-1')



else:
    print(n-x)

Solution (Python):

getS = lambda: input().strip()
getN = lambda: int(input())
getList = lambda: list(map(int, input().split()))
getZList = lambda: [int(x) - 1 for x in input().split()]
 
n, m = getList()
nums = getList()
sn = sum(nums)
if sn > n:
  print(-1)
else:
  print(n - sn)

Solution (Python):

ri = lambda S: [int(v) for v in S.split()]

N, M = ri(input())
A = ri(input())
s = sum(A)
print(N - s if N - s >= 0 else -1)

Solution (Python):
n, m = map(int,input().split())
a = list(map(int,input().split()))
for i in a:
  n -= i
if n >= 0:
  print(n)
else:
  print(-1)

Solution (Python):
n,m = map(int, input().split())
a = list(map(int, input().split()))

for i in a:
    n -= i
if n < 0:
    print(-1)
else:
    print(n)

Solution (Python):
n, m = [int(i) for i in input().split()]
a = [int(i) for i in input().split()]
for ai in a:
  n -= ai
n = -1 if n < 0 else n
print(n)

Solution (Python):
N,M = map(int,input().split())
A_lis = map(int,input().split())

can_play = N - sum(A_lis)
print(can_play if can_play >= 0 else -1)

Solution (Python):


n, m = map(int, input().split())
a = list(map(int, input().split()))

ans = n - sum(a)

if ans < 0:
    print(-1)
else:
    print(ans)

Solution (Python):
import sys

nm = input().split()
N = int(nm[0])
M = int(nm[1])

As = [int(a) for a in input().split()]

s = sum(As)

if N >= s:
    ans = N - s
    print(ans)
else:
    print("-1")

Solution (Python):
x, _ = map(int,input().split())
a = list(map(int,input().split()))
y = x - sum(a)
if y < 0:
    print(-1)
else:
    print(y)

Solution (Python):
H, M = map(int, input().split())
A = list(map(int, input().split()))
for i in A:
  H -= i
if H < 0:
  print("-1")
else:
  print(H)

Solution (Python):
N, M = map(int, input().split())

A = list(map(int, input().split()))

Sam = sum(A)

if N >= Sam:
    print(N - Sam)
else:
    print(-1)

Solution (Python):
n,m=map(int,input().split())
A=list(map(int,input().split()))
for i in range(m):
  n-=A[i]
if n<0:
  print(-1)
else:
  print(n)

Solution (Python):
n, m = map(int,input().split())
a = list(map(int,input().split()))

aa = sum(a) 
if n<aa:
    print(-1) 
else:
    print(n-aa)

Solution (Python):
N, M = input().split()
N = int(N)
M = int(M)
A = list(map(int, input().split()))
LA = len(A)
i = 0
SUM = 0

for i in range(LA):
    SUM = SUM + A[i]
    
if SUM > N:
    print('-1')
    
else:
    print(N - SUM)

Solution (Python):
N, M = map(int, input().split())
A = list(map(int,input().split()))
a = sum(A)
 
if N >= a:
  print(int(N-a))
else:
  print(-1)

Solution (Python):
N,M = map(int, input().split())
A = list(map(int, input().split()))

print(max(-1, N-sum(A)))

Solution (Python):
N, M = map(int, input().split()) 
A = list(map(int, input().split()))
 

s = sum(A)
ans = -1
if N >= s: ans = N - s
print(ans)

Solution (Python):
n = input()
n = n.split()
m = int(n[1])
n = int(n[0])
a = input()
a = a.split()
b = int(a[0])
for c in range(m-1):
    b = b + int(a[c+1])
if n - b < 0:
    print("-1")
else:
    print(n-b)

Solution (Python):
n,m=map(int,input().split())
a=list(map(int,input().split()))

ans=0
for i in range(m) :
    ans = ans+a[i]

day=n-ans






print(day if day >= 0 else "-1")

Solution (Python):
N,M=map(int,input().split())
A=list(map(int,input().split()))
for i in range(M):
    N-=A[i]
    if N<0:
        print(-1)
        exit()
print(N)

Solution (Python):
n,m = map(int,input().split())
a = list(map(int,input().split()))
print(max(n-sum(a),-1))

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))

sum_homework_day = sum(A)

if sum_homework_day > N:
    print(-1)
else:
    print(N - sum_homework_day)

Solution (Python):
N, M = map(int,input().split())
A=list(map(int, input().split()))
for i in A:
    if sum(A) > N:
        ans = -1
    else:
        ans = N - sum(A)
print(ans)

Solution (Python):
N,M = map(int,input().split())
A = [int(x) for x in input().split()]

if N - sum(A) >= 0 :
    print(N-sum(A))
else :
    print("-1")

Solution (Python):
n, m = (int(x) for x in input().split())
list_a = [int(x) for x in input().split()]

for i in range(0, m):
    n -= list_a[i]
    if n < 0:
        print('-1')
        exit()
print(n)

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))
if N - sum(A) >= 0:
    print(N - sum(A))
else:
    print("-1")

Solution (Python):
n,m = map(int, input().split())
x = n-sum(list(map(int, input().split())))

if x < 0: 
    print(-1)
else:
    print(x)

Solution (Python):
def main():
    n, m = map(int, input().split())
    a_lst = list(map(int, input().split()))
    total = sum(a_lst)

    if total > n:
        ans = -1
    else:
        ans = n - total

    print(ans)


if __name__ == "__main__":
    main()

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))

for time in a:
    n -= time
    if n<0:
        n = -1
        break

print(n)

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))

ans = N - sum(A)
if ans < 0:
    ans = -1

print(ans)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
x = n - sum(a)
print(x if x >= 0 else -1)

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))
print(max(-1, N - sum(A)))

Solution (Python):
n,m=map(int,input().split())
L=list(map(int,input().split()))
if sum(L)<=n:
  print(n-sum(L))
else:
  print(-1)

Solution (Python):
n,m = map(int,input().split())
a = list(map(int,input().split()))

ans = n - sum(a)
if ans < 0:
    print(-1)
else:
    print(ans)

Solution (Python):
def resolve():
    N, M = list(map(int, input().split()))
    A = list(map(int, input().split()))
    print(-1 if sum(A)>N else N-sum(A))



if '__main__' == __name__:
    resolve()

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))

N = N - sum(A)
if N >= 0:
  print(N)
else:
  print(-1)

Solution (Python):
n,k=map(int,input().split())
l=list(map(int,input().split()))
if (n-sum(l))<0:
  print(-1)
else:
  print(n-sum(l))

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))
availability = N
for i in range(M):
    availability -= A[i]

if availability < 0:
    print(-1)
else:
    print(availability)

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))
if N>=sum(A):
    print(N-sum(A))
else:
    print(-1)

Solution (Python):
r=input().split()
N=int(r[0])
d_pre=input().split()
d=[int(s) for s in d_pre]
ans=N-sum(d)
if ans>=0:
    print(ans)
else:
    print(-1)

Solution (Python):
N,M = map(int, input().split())
A = list(map(int, input().split()))
ans = N - sum(A)
if ans < 0:
    ans = -1
print(ans)

Solution (Python):

n,m = map(int, input().split( ))
A = list(map(int, input().split( )))
s = sum(A)
if n >= s:
  print(n-s)
else:
  print(-1)

Solution (Python):
def main():
    N,M = map(int,input().split())
    A = list(map(int,input().split()))
    cnt = 0

    for i in range(M):
        cnt += A[i]

    if  N < cnt:
        return -1
    else:
        return N - cnt

print(main())

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))
count = 0

for i in range(M):
  count += A[i]

if(count <= N):
  print(N - count)
else:
  print(-1)

Solution (Python):
N,M = map(int, input().split())
Ai = [int(i) for i in input().split()]

remain = N - sum(Ai)
if remain < 0:
    print("-1")
else:
    print(f"{remain}")

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))

total = sum(A)
if total > N:
    print(-1)
else:
    print(N - total)

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))

total = sum(A)
if total > N:
    print(-1)
else:
    print(N - total)

Solution (Python):
n, m = map(int, input().split())
a_array = list(map(int, input().split()))

sum_a = sum(a_array)

if n - sum_a < 0:
    ans = -1
else:
    ans = n - sum_a

print(ans)

Solution (Python):
N,M = list(map(int,input().split()))
A = list(map(int,input().split()))

sum = 0
for i in range(M):
	sum = sum + A[i]

if N > sum:
	print(N - sum)
elif N == sum:
	print(0)
else:
	print(-1)

Solution (Python):
N,X = map(int,input().split())
Y = N - sum(map(int,input().split()))
print(("-1",Y)[Y >= 0])

Solution (Python):
n, m = map(int,input().split())
lst = list(map(int,input().split()))
x = 0
for i in range(m):
  x = x + lst[i]
if (x > n):
  print("-1")
else:
  print(n - x)

Solution (Python):
def main():
    N, M = map(int, input().split())
    A = list(map(int, input().split()))
    if sum(A) > N:
        print(-1)
    else:
        print(N - sum(A))


if __name__ == '__main__':
    main()

Solution (Python):
N, M = map(int, input().split())

hw_list = map(int, input().split())
for hw in hw_list:
    N -= hw

if N >= 0:
    print(N)
elif N < 0:
    print(-1)

Solution (Python):
n,m =map(int, input().split())
a = list(map(int, input().split()))
if n < sum(a):
    print(-1)
else:
    print(n-sum(a))

Solution (Python):
n,m = map(int,input().split())
a = map(int,input().split())
x = n-sum(a) 
if x >= 0:
    print(x)
else:
    print(-1)

Solution (Python):
N, M = map(int, input().split())
day = list(map(int, input().split()))
for i in range(M):
    N -= day[i]
    if N < 0:
        print(-1)
        exit()
print(N)

Solution (Python):
n, m = map(int,input().split())
A = tuple(map(int,input().split()))
days = 0
for i in A:
    days += i
if n < days:
    print(-1)
else:
    print(n-days)

Solution (Python):
n,m = map(int,input().split())
a = list(map(int,input().split()))
print('-1' if sum(a)>n else n-sum(a))

Solution (Python):
N, M = map(int, input().split())

A_list = list(map(int, input().split()))

for i in range(M):
    N -= A_list[i]
    if N < 0:
        print(-1)
        break
    if i == M-1:
        print(N)

Solution (Python):
N, M = map(int, input().split())
A=[int(x) for x in input().split()]
ans=N-sum(A)
print(ans if ans>=0 else -1)

Solution (Python):
n,m=map(int,input().split())
l=list(map(int,input().split()))
s=sum(l)
d=n-s
print(max(-1,d))

Solution (Python):
n,m = map(int,input().split())
a = list(map(int,input().split()))
if n - sum(a) < 0:
    print(-1)
else:
    print(n - sum(a))

Solution (Python):
n = list(map(int, input().split(' ')))
m = list(map(int, input().split(' ')))
if n[0] >=  sum(m):
    print(n[0] - sum(m))
else:
    print(-1)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))

if n-sum(a) >= 0:
  print(n-sum(a))
else:
  print("-1")

Solution (Python):
n, m = map(int, input().split())
A = list(map(int, input().split()))
if sum(A) > n:
	print(-1)
else:
	print(n - sum(A))

Solution (Python):
n, m = map(int,input().split())
a = list(map(int, input().split()))
t = 0

for i in range(m):
    t += a[i]
    if t > n:
        break
if t > n:
    ans = -1
else:
    ans = n - t

print(ans)

Solution (Python):
n, m = map(int, input().split())

a = list(map(int, input().split()))

for i in range(m):
    n -= a[i]

if n >= 0:
    print(n)
else:
    print(-1)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))

ans = n - sum(a)
print(-1 if ans < 0 else ans)

Solution (Python):
n,m=map(int,input().split())

a=list(map(int,input().split()))
cnt=0

for i in a:
    cnt+=i
   
if n-cnt<0:
    print(-1)

else:
    print(n-cnt)

Solution (Python):
n,m = map(int, input().split())
l = list(map(int, input().split()))
c = 0
for i in l:
  c += i
print(n-c if n-c >= 0 else -1)

Solution (Python):
n, k = list(map(int, input().split()))
a = list(map(int, input().split()))

if sum(a) > n:
    print(-1)
else:
    print(n - sum(a))

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
if sum(a) > n:
    print(-1)
else:
    print(n - sum(a))

Solution (Python):
n,m = map(int,input().split())
a = list(map(int,input().split()))
a = sum(a)
if a > n:
  print(-1)
else:
  print(n-a)

Solution (Python):
x=input()
y=x.split(" ")
n=int(y[0])
g=input()
h=g.split(" ")
su=0
for b in h:
    su+=int(b)
if(su>n):
    print(-1)
else:
    print(n-su)

Solution (Python):
N, M = map(int, input().split())
A = map(int, input().split())
print(max(-1, N - sum(A)))

Solution (Python):
N,M = map(int,input().split())
A = list(map(int,input().split()))

if sum(A)>N:
  print(-1)
else:
  print(N-sum(A))

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
for i in range(m):
    n = n - a[i]
print(int(n) if n >= 0 else "-1")

Solution (Python):
N, M = map(int, input().split())
A = sum(map(int, input().split()))
if N-A >= 0:
    print(N-A)
else:
    print(-1)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))

total = 0
for i in range(m):
    total = total + a[i]
if (n -total) < 0:
    print(-1)
else:
    print(n - total)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
x = 0
for i in range(m):
    x += a[i]
if n - x >= 0:
    print(n - x)
else:
    print(-1)

Solution (Python):
n,m = map(int,input().split())
alist = list(map(int,input().split()))

d = n - sum(alist)
if d < 0:
    print(-1)
else:
    print(d)

Solution (Python):
N,M = map(int,input().split())
A = list(map(int,input().split()))

if sum(A) <= N:
    print(N-sum(A))
else:
    print(-1)

Solution (Python):
n,m = map(int,input().split())
a = list(map(int,input().split()))
if n>=sum(a):
    print(n-sum(a))
else:
    print(-1)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int,input().split()))
if (n - sum(a)) >= 0:
  print(n-sum(a))
else:
  print(-1)

Solution (Python):
a = list(map(int, input().split()))
b = list(map(int, input().split()))
if a[0] - sum(b) >= 0:
  print(a[0] - sum(b))
else:
  print(-1)

Solution (Python):
day, m = list(map(int, input().split()))
s = sum(map(int, input().split()))
if s > day:
    print(-1)
else:
    print(day - s)

Solution (Python):
N,M=map(int,input().split())
A_M=list(map(int,input().split()))
if N >= sum(A_M):
    print(N-sum(A_M))
else:
    print(-1)

Solution (Python):
n,m = map(int,input().split())
A = list(map(int,input().split()))
if (sum(A) <= n):
  print(n - sum(A))
else:
  print("-1")

Solution (Python):
import math
def main():
    n,m = map(int,input().split())
    a = list(map(int,input().strip().split()))
    
    if n >= sum(a):
        print(n-sum(a))
        return 
    else:
        print(-1)
        return

main()

Solution (Python):
def solve():
    N,M = [int(i) for i in input().split()]
    A = [int(i) for i in input().split()]
    freedays = N - sum(A)
    if freedays < 0:
        print(-1)
    else:
        print(freedays)

if __name__ == "__main__":
    solve()

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
if n - sum(a) < 0:
    print(-1)
else:
    print(n - sum(a))

Solution (Python):
N,M = map(int,input().split())
A = list(map(int,input().split()))

homeworks = 0
for i in A:
    homeworks += i

if N >= homeworks:
    print(N-homeworks)
else:
    print(-1)

Solution (Python):
n, m = map(int,input().split())
a = list(map(int,input().split()))

if n - sum(a) >= 0:
    print(n-sum(a))
else:
    print(-1)

Solution (Python):

N, M = map(int, input().split())
A = list(map(int, input().split()))
ans = max(-1, N - sum(A))
print(ans)

Solution (Python):
n,m = map(int, input().split())
a = list(map(int, input().split()))
syukudai = 0

for i in range(m):
    syukudai += a[i]
    if syukudai > n:
        print(-1)
        break
else:
    print(n-syukudai)

Solution (Python):
n,m=map(int,input().split())
a=list(map(int,input().split()))

for aa in a:
  n-=aa
if n >=0:
  print(n)
else:
  print(-1)

Solution (Python):
N, _ = map(int, input().split())
A = sum(map(int, input().split()))
print(N-A) if N >= A else print(-1)

Solution (Python):
N,M=map(int,input().split())
A=list(map(int,input().split()))
K=N-sum(A)
if K<0:
    print(-1)
else:
    print(K)

Solution (Python):
N,M = map(int,input().split())
MM = map(int,input().split())
total = 0
for i in MM:
 
  total +=i
ans = N -total
if ans >= 0:
  print(ans)
else:
  print(-1)

Solution (Python):
n, m = map(int,input().split())

a = list(map(int,input().split()))

a_sum = sum(a)

if n - a_sum >= 0:
    print(n-a_sum)
else:
    print(-1)

Solution (Python):

if __name__ == '__main__':
    """
    :param N: days
    :param M: num of homeworks
    :param A: days to finish each homework
    """
    N, M = map(int, input().split())
    A = list(map(int, input().split()))
    need = sum(A)
    if N >= need:
        print(N-need)
    else:
        print(-1)

Solution (Python):

def main():
    N, M = map(int, input().split())
    A = [int(x) for x in input().split()]

    if N >= sum(A):
        print(N - sum(A))
    else:
        print(-1)


if __name__ == '__main__':
    main()

Solution (Python):
n,m=map(int,input().split())
a=[int(i) for i in input().split()]
print(max(-1,(n-sum(a))))

Solution (Python):
n, m = map(int, input().split())

a = list(map(int, input().split()))

s = int(sum(a))

if n > s:
    print(n-s)
elif n == s:
    print(0)
else:
    print(-1)

Solution (Python):
N,M=map(int,input().split())
A=map(int,input().split())
print(max(-1,N-sum(A)))

Solution (Python):
N,M=map(int,input().split())
A=[int(x) for x in input().split()]
print(max(-1,(N-sum(A))))

Solution (Python):
n,m=map(int,input().split())
a=list(map(int,input().split()))
day=sum(a)
if n>=day:
    print(n-day)
else:
    print("-1")

Solution (Python):
import bisect,collections,copy,heapq,itertools,math,numpy,string
import sys
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())

N, M = MI()
A = LI()
ans = N - sum(A)
if ans >= 0:
    print(ans)
else:
    print(-1)

Solution (Python):
N, M = [int(i) for i in input().split(' ')]
A = [int(i) for i in input().split(' ')]
r = N - sum(A)
print(r if r >= 0 else -1)

Solution (Python):
n,m = map(int,input().split())
a = [int(s) for s in input().split()]
daycount = 0
for i in range(m):
    daycount += a[i]
if n - daycount >= 0:
    print(n - daycount)
else:
    print(-1)

Solution (Python):
n,m=map(int,input().split())
a =list(map(int,input().split()))
day = 0
for i in range(m):
    day += a[i]
print(-1 if day>n else n - day)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
ct = 0
for i in range(m):
    ct += a[i]

if n - ct >= 0:
    print(n - ct)
else:
    print(-1)

Solution (Python):
N, M = list(map(int, input().split()))
A = list(map(int, input().split()))
AS = sum(A)
if N >= AS:
	print(N - AS)
else:
	print(-1)

Solution (Python):
import sys
read = sys.stdin.read
readlines = sys.stdin.readlines

def main():
    n, m, *a = map(int, read().split())
    suma = sum(a)
    if n < suma:
        print(-1)
    else:
        print(n - suma)

if __name__ == '__main__':
    main()

Solution (Python):
N,M=map(int,input().split())
A=list(map(int,input().split()))
ans=N-sum(A)
print(ans if ans>=0 else -1)

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))
sum_A = sum(A)
if sum_A > N:
    print(-1)
else:
    print(N - sum_A)

Solution (Python):
n,m = map(int,input().split())
A = list(map(int,input().split()))

for a in A:
    n-=a
if n<0:
    n=-1 
print( n )

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))

if sum(A) <= N:
    print(N - sum(A))
else:
    print(-1)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))

x = n - sum(a)
print(x) if x >= 0 else print(-1)

Solution (Python):
N, M = map(int, input().split())
Alst = list(map(int, input().split()))
k = sum(Alst)
ans = N - k
if ans >= 0:
    print(ans)
else:
    print(-1)

Solution (Python):
tmp = input().split(" ")
N = int(tmp[0])
M = int(tmp[1])
ary = list(map(lambda n: int(n), input().split(" ")))
n = sum(ary)
print(-1) if N < n else print(N - n)

Solution (Python):
N, M = map(int, input().split())
print(max(-1, N-sum(map(int, input().split()))))

Solution (Python):
n, m = map(int, input().split())
am = list(map(int, input().split()))

if n-sum(am) < 0:
    print(-1)
else:
    print(n-sum(am))

Solution (Python):
n, m = map(int, input().split(" "))
a = map(int, input().split(" "))

z = n - sum(a)

print(z if z >=0 else -1)

Solution (Python):
N, M = map(int, input().split())
A = list(map(int, input().split()))

ans = N - sum(A)
if ans >= 0:
  print(ans)
else:
  print(-1)

Solution (Python):
N,M=map(int,input().split())
A=list(map(int,input().split()))
if sum(A) > N:
    print(-1)
else:
    print(N-sum(A))

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
s = sum(a)
if n >= s:
    print(n-s)
else:
    print(-1)

Solution (Python):
N, M = map(int, input().split(' '))
A_ls = list(map(int, input().split(' ')))

if sum(A_ls) > N:
    print(-1)
else:
    print(N - sum(A_ls))

Solution (Python):
def main():
    N, _ = map(int, input().split())
    A = map(int, input().split())

    tot = sum(A)

    diff = max(-1, N - tot)

    print(diff)


if __name__ == '__main__':
    main()

Solution (Python):
N,M = map(int,input().split())
A = list(map(int,input().split()))

A_sum = sum(A)

if N - A_sum>=0:
    print(N - A_sum)
else:
    print(-1)

Solution (Python):
N,M = map(int,input().split())
A = list(map(int,input().split()))

A_sum = sum(A)
ans = N - A_sum

if ans>=0:
    print(ans)
else:
    print(-1)

Solution (Python):
N,M = list(map(int,input().split()))
print( max(-1, N-sum(list(map(int,input().split()))) ) )

Solution (Python):
n,m = map(int,input().split())
a = list(map(int,input().split()))
ans = 0
for i in range(m):
    ans += a[i]
if n < ans:
    print(-1)
else:
    print(n-ans)

Solution (Python):
a, n = input().split()
a = int(a)
n = int(n)
p = list(map(int, input().split()))

c = 0
for i in range(n):
  c += p[i]
  
if c > a:
  print(-1)
else:
  print(a-c)

Solution (Python):
N,M = map(int,input().split())
L = map(int,input().split())
work = 0
for i in L :
    work += i
if N >= work :
    print ( N - work )
else :
    print ("-1")

Solution (Python):
N,M = map(int,input().split())
L = map(int,input().split())
res = 0
for i in L :
    res += i
if N >= res :
    print ( N - res )
else :
    print ("-1")

Solution (Python):
N, M = map(int, input().split())
A = sum(list(map(int, input().split())))
if A>N:
    print(-1)
else:
    print(N-A)

Solution (Python):
N, M = map(int, input().split())
A = sum(list(map(int, input().split())))

free_days = N - A
if (free_days >= 0):
    print(free_days)
else:
    print('-1')

Solution (Python):
n, m=map(int, input().split())
x = list(map(int, input().split()))

if sum(x) <= n:
  print(n-sum(x))
else:
  print("-1")

Solution (Python):
N,M=map(int,input().split())
A=list(map(int,input().split()))
S=sum(A)
if N<S:
    print(-1)
else:
    print(N-S)

Solution (Python):
N, M = map(int, input().split())
ans = 0
for i in map(int,input().split()):
    ans += i

if ans > N:
    print('-1')
else:
    print(N-ans)

Solution (Python):
n,m = (int(i) for i in input().split())
A = [int(i) for i in input().split()]
ans = n - sum(A)
if ans <= -2: print(-1)
else: print(ans)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
print(max(n - sum(a), -1))

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))
d = n - sum(a)
print(d if d >= 0 else -1)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))

if n >= sum(a):
    print(n - sum(a))
else:
    print(-1)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))

ans = n - sum(a)
if ans < 0:
    ans = -1
print(ans)

Solution (Python):
n ,m = map(int, input().split())
a = list(map(int, input().split()))

if sum(a) > n:
    print(-1)
else:
    print(n - sum(a))

Solution (Python):
a,b=map(int,input().split())
c=list(map(int,input().split()))
c=sum(c)
if a<c:
  print(-1)
else:
  print(a-c)

Solution (Python):
a=list(map(int,input().split()))
b=list(map(int,input().split()))
if sum(b)>a[0]:
  print(-1)
elif sum(b)==a[0]:
  print(0)
else:
  print(a[0]-sum(b))

Solution (Python):
import sys
readline = sys.stdin.buffer.readline
n, m = map(int, readline().split())
a = map(int, readline().split())
print(h if (h := n - sum(a)) >= 0 else -1)

Solution (Python):
n, m = list(map(int, input().split()))
a = list(map(int, input().split()))
s = sum(a)
if s <= n:
    print(n - s)
else:
    print(-1)

Solution (Python):
n, m = map(int, input().split())
a = map(int, input().split())

ans = n - sum(a)
if ans < 0:
    print(-1)
else:
    print(ans)

Solution (Python):
import sys, bisect, math, itertools, string, queue, copy
import numpy as np
import scipy
from collections import Counter,defaultdict,deque
from itertools import permutations, combinations
from heapq import heappop, heappush
from fractions import gcd
input = sys.stdin.readline
sys.setrecursionlimit(10**8)
mod = 10**9+7
def inp(): return int(input())
def inpm(): return map(int,input().split())
def inpl(): return list(map(int, input().split()))
def inpls(): return list(input().split())
def inplm(n): return list(int(input()) for _ in range(n))
def inplL(n): return [list(input()) for _ in range(n)]
def inplT(n): return [tuple(input()) for _ in range(n)]
def inpll(n): return [list(map(int, input().split())) for _ in range(n)]
def inplls(n): return sorted([list(map(int, input().split())) for _ in range(n)])

n,m = inpm()
a = inpl()

if np.sum(a) > n:
    ans = -1
else:
    ans = n - np.sum(a)
print(ans)

Solution (Python):
n, m = map(int, input().split())
a = list(map(int, input().split()))

if n - sum(a) < 0:
    print(-1)
else:
    print(n - sum(a))

Solution (Python):


def main():

    N, M = map(int, input().split())
    A = list(map(int, input().split()))

    sumA = sum(A)

    if sumA > N:
        ans = -1
    
    else:
        ans = N - sumA

    print(ans)


if __name__ == "__main__":
    main()

Solution (Python):
m,n,*aa = map(int, open(0).read().split())
ans = m-sum(aa)
if ans<0:
  print(-1)
else:
  print(ans)

Solution (Python):
N,M = list(map(int,input().split()))
A = list(map(int,input().split()))
t = N - sum(A)
if t < 0:
    print(-1)
else:
    print(t)

Solution (Python):
N,M = map(int,input().split())
A = list(input().split())

for i in range(M):
  N -= int(A[i])

if N < 0:
  print(-1)
else:
  print(str(N))