Go: package main

import "fmt"

func main() {
	var m, a, book int
	fmt.Scan(&m, &a, &book)

	if nokori := m - book; nokori < 0 {
		if nokori = nokori + a; nokori < 0 {
			fmt.Println("NA")
		} else {
			fmt.Println(a - nokori)
		}
	} else {
		fmt.Println(0)
	}
}

Python: m, f, b = map(int,input().split())
 
if m >= b:
  print(0)
if m < b:
  a = b-m
  if b-m <= f:
    print(a)
  else:
    print('NA')

Python: a,b,c, = map(int, input().split())
if a>= c:
  print(0)
else:
  d = c - a
  if d <= b:
    print(d)
  else:
    print("NA")

Python: m,f,b=map(int,input().split())
if m+f<b:
  print("NA")
elif m>=b:
  print(0)
else:
  print(b-m)

Python: m, f, b = map(int,input().split())
if m >= b:
  print('0')
if m < b <= m + f:
  print(b - m)  
if m + f < b:
  print('NA')

Python: m, f, b=map(int,input().split(" "))

if m>b:
  print("0")

else:
  if m+f<b:
    print("NA")
  else:
    print(b-m)

Python: m,f,b=map(int,input().split())
if m+f>=b:
    if m>b:
        print("0")
    elif m<b:
        print(b-m)
elif m+f<b:
    print("NA")

Python: m, f ,b = map(int, input().split())
lending = max(b - m, 0)
if lending <= f:
    print(lending)
else:
    print("NA")

Python: m, f, b = map(int, input().split())
print(max(0, b - m) if m + f >= b else "NA")

Python: m,f,b=map(int,input().split())
if m+f < b:
    print("NA")
elif m>=b:
    print(0)
else:
    print(b-m)

Python: m, f, b = map(int, input().split())
if b <= m:
    print(0)
elif b <= m+f:
    print(b-m)
else:
    print("NA")

Python: m,f,b = map(int, input(). split())

if b <= m:
  print('0')
elif b-m <= f:
  print(b-m)
else:
  print('NA')

Python: m, f, b = map(int, input().split())

if m >= b:
    print("0")
elif m + f >= b:
    print(b - m)
else:
    print("NA")

Python: m, f, b = map(int, input().split())

if m + f < b:
    print("NA")
elif m >= b:
    print(0)
else:
    print(b - m)

Python: m,f,b = [int(i) for i in input().split()]

ans = b - m
if ans <= 0:
    print(0)
elif ans <= f:
    print(ans)
else:
    print("NA")

Python: m, f, b = list(map(int, input().split()))
print('NA' if m+f<b else max(0, b-m))

Python: # coding=utf-8

m, f, b = map(int, input().split())

if m+f < b:
    print("NA")
elif m >= b:
    print(0)
else:
    print(b-m)

Python: import sys
m,f,b=map(int,input().split())
sum1=m+f
if(sum1>=b):
    if(m>=b):
        rental=0
        print(rental)
    else:
        rental=b-m
        print(rental)
else:
    print('NA')

Python: m,f,b = map(int,input().split())
if m+f < b:
    print("NA")
elif m >= b:
    print(0)
else:
    print(b-m)

Python: m, f, b = map(int, input().split())

x = b - m

if(x <= 0):
    print("0")

elif(x <= f):
    print(x)
    
else:
    print("NA")

Python: m,f, b = map(int, input().split())
if b - m > 0:
  if f >= (b - m):
    print(b - m)
  else:
    print("NA")
else:
  print("0")

Python: m, f, b = map(int, input().split())

if b>m+f:
    print('NA')
else:
    print(max(b-m, 0))

Python: m, f, b = map(int, input().split())
if m  + f < b:
    print("NA")
elif  m >= b:
    print(0)
else:
    print(b - m)

Python: m, f, b = list(map(int, input().split()))
if m >= b:
    print(0)
elif (m < b) and (m + f >= b):
    print(b-m)
else:
    print("NA")

Python: a,b,c, = map(int, input().split())
if a>= c:
 print(0)
else:
 d = c - a
 if d <= b:
   print(d)
 else:
   print("NA")

Python: m, f, b = map(int, input().split())
print("NA"*(m+f < b) + (m+f >= b)*str(max(0, b-m)))

Python: m,f,b = map(int,input().split())

if m - b > 0:
  print(0)
elif m + f >= b:
  print(b - m)
elif m + f < b:
  print("NA")

Python: M, F, B = map(int, input().split())
if M+F<B:
	print('NA')
else:
	print(max(B-M, 0))

Python: a,b,c=map(int,input().split())
if c <= a:
 print("0")
elif c <= a+b:
 print(c-a)
else:
 print("NA")

Python: m,f,b=map(int,input().split())
if(m+f<b):
  print("NA")
else:
  if(m>b):
    print(0)
  else:
    print(b-m)

Python: m, f, b = map(int, input().split())
if m  + f < b:
    print("NA")
elif  m >= b:
    print(0)
else:
    print(b - m)

Python: m, f, b = map(int, input().split())

if m + f < b:
    print("NA")
elif m > b:
    print("0")
else:
    print(b - m)

Python: m,f,b = map(int,input().split())
if m+f >= b:
    print(max(0,b-m))
else:
    print("NA")

Python: 
m, f, b = map(int, input().split())
a = b - m

if a <= 0:
    print(0)
elif a <= f:
    print(a)
else:
    print("NA")

Python: m, f, b = map(int, input().split())
print(0 if m >= b else "NA" if m+f < b else b-m)

Python: m,f,b=map(int,input().split())
if m>=b:
    print(0)
elif m+f<b:
    print('NA')
else:
    print(b-m)

Python: m,f,b = map(int, input().split())
if m > b:
    print(0)
else:
    d = b - m
    if d <= f:
        print(d)
    else:
        print("NA")

Python: m,f,b=map(int,input().split())
if m<b:
    if b-m>f:
        print("NA")
    else:
        print(b-m)
else:
    print(0)

Python: m,f,b = map(int, input().split())
if b-m>0 :
  if b-m<=f :
    print(b-m)
  else:
    print('NA')
else:
  print(0)

Python: a,b,c = map(int, input().split())
if a >= c:
  print(0)
else:
  d = c - a
  if d <= b:
    print(d)
  else:
    print("NA")

Python: m,f,b=map(int,input().split())
if m >= b:
    print(0)
elif m+f >= b:
    print(b-m)
else:
    print('NA')

Python: m,f,b= map(int,input().split())

if b-m < 0:
    print(0)
elif b-m-f>0:
    print("NA")
else:
    print(b-m)

Python: a,b,c=map(int,input().split())
if a>=c:
    print(0)
elif a+b>=c:
    print(c-a)
elif a+b<c:
    print("NA")

Python: a,b,c = map(int,list(input().split(" ")))
m = max(0,c-a)
if(a+b>=c):
      print(m)
else:
      print("NA")

Python: m, f, b = map(int, input().split())
if m > b:
    print(0)
elif m + f >= b:
    print(b - m)
else:
    print('NA')

Python: i = input()
m,f,b = map(int,i.split())
if m >= b:
    print(0)
elif (m+f) < b:
    print('NA')
else:
    print(b - m)

Python: m,f,b=map(int,input().split())
if m+f<b:
    print('NA')
elif m>b:
    print('0')
else:
    print(b-m)

Python: m, f, b = input().split()
m = int(m)
f = int(f)
b = int(b)

if m >= b:
  print(0)
elif m + f >= b:
  print(b - m)
else:
  print('NA')

Python: m,f,b = [ int(s) for s in input().split() ]
  
x = b-m

if m >= b:
    print(0)
elif f >= x:
    print(x)
else:
    print('NA')

Python: m,f,b = map(int, input().split())

if m >= b:
    print(0)
elif (m+f) >= b:
    print(b-m)
else:
    print("NA")

Python: m,f,b=map(int,input().split())
ans=0
if m>b:
    ans=0
elif m<b:
    ans=b-m
elif m+f<b:
    ans="NA"
print(ans)

Python: a,b,c = map(int, input().split())
if a >= c:
    print(0)
else:
    d = c - a
    if d <= b:
        print(d)
    else:
        print("NA")

Python: m, f, b = map(int, input().split())
if m + f < b:
        print("NA")
elif m >= b:
    print(0)
else:
    print(b - m)

Python: m,f,b=map(int,input().split())

if m>b:
   print(0)

elif b-m<=f:
   print(b-m)
else:
   print("NA")

Python: def main():
    m,f,b = map(int,input().split())

    if m+f < b:
        return 'NA'
    return max(0,b-m)

if __name__ == '__main__':
    print(main())

Python: data = input()
my_money, a_money, price = map(int, data.split())
if my_money >= price:
    print(0)
elif my_money < price:
    if (my_money + a_money) >= price:
        print(price - my_money)
    else:
        print('NA')

Python: m, f, b = map(int,input().split())

if m >= b:
  print(0)
if m < b:
  a = b-m
  if b-m <= f:
    print(a)
  else:
    print('NA')

Python: a,b,c = map(int, input().split())
if a >= c:
    print(0)
else:
    d = c - a
    if d <= b:
        print(d)
    else:
        print("NA")

Python: m, f, b = map(int, input().split())
if b <= m:
    print(0)
elif b <= m + f:
    print(b-m)
else:
    print("NA")

Python: #!/usr/bin/env/ python

Python: m,f,b = map(int,input().split())

a = b-m
if f>= a and a > 0 :
     print(a)
elif a<0 :
  print(0)
else :
    print('NA')

Python: m,f,b=map(int,input().split())
if m>=b:
    print(0)
elif m+f>=b:
    g=b-m
    print(g)
else :
    print("NA")