Go: package main

import (
	"bufio"
		"os"
	"strings"
	"strconv"
		"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	for scanner.Scan() {
		input := strings.Split(scanner.Text(), " ")
		ele_t1 := [3]int{}
		ele_t2 := [3]int{}
		for i := range ele_t1 {
			ele_t1[i], _ = strconv.Atoi(input[i])
			ele_t2[i], _ = strconv.Atoi(input[i+3])
		}
		if ele_t1[0] < 0 || ele_t1[1] < 0 || ele_t1[2] < 0 ||
			ele_t2[0] < 0 || ele_t2[1] < 0 || ele_t2[2] < 0 {
				break
		}
		// t1 := time.Date(ele_t1[0], time.Month(ele_t1[1]), ele_t1[2], 0, 0, 0, 0, time.UTC)
		// t2 := time.Date(ele_t2[0], time.Month(ele_t2[1]), ele_t2[2], 0, 0, 0, 0, time.UTC)
		// diff := t2.Sub(t1)
		// fmt.Printf("%v\n", int64(diff/(time.Hour*24)))
		fmt.Println(ut2jd(ele_t2[0], ele_t2[1], ele_t2[2])-ut2jd(ele_t1[0], ele_t1[1], ele_t1[2]))
	}
}

func ut2jd(year, month, day int) int {
	if month <= 2 {
		year--
		month += 12
	}
	s := 3 + year/4 - year/100 + year/400
	s += 1720994 + year*365 + (month+1)*30 + (month+1)*3/5 + day
	return s
}

Python: import time
from datetime import date

#solve function
def solve(str_dates):
    dates = []
    for i in range(len(str_dates)):
        dates.append(int(str_dates[i]))

    date_start = date(dates[0], dates[1], dates[2])
    date_end = date(dates[3], dates[4], dates[5])

    return (date_end - date_start)


#main function
if __name__ == '__main__':
    while True:
        dates = input().split()

        if dates[0] == "-1":
            break

        date_diff = solve(dates)

        print(date_diff.days)

Python: import datetime as D
while 1:
  a,b,c,d,e,f=x=map(int,raw_input().split(" "))
  if min(x)<0: break
  print (D.date(d,e,f)-D.date(a,b,c)).days

Python: from datetime import date
while 1:
    t=list(map(int,input().split()))
    if t[0]<0:break
    print((date(*t[3:])-date(*t[:3])).days)

Python: import datetime as D
while 1:
  a,b,c,d,e,f=map(int,raw_input().split())
  try: print (D.date(d,e,f)-D.date(a,b,c)).days
  except: break

Python: import datetime
while 1:
	y1,m1,d1,y2,m2,d2=map(int,raw_input().split())
	if y1==-1:break
	print (datetime.date(y2,m2,d2)-datetime.date(y1,m1,d1)).days

Python: def uru(y):
    return y % 4 == 0 and y % 100 != 0 or y % 400 == 0

def y_to_d(y):
    ret = 0
    for i in range(y):
        if uru(i):
            ret += 366
        else:
            ret += 365
    return ret

month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]


def m_to_d(y, m):
    m -= 1
    ret = 0
    for i in range(m-1):
        ret += month[i]
    if m > 2 and uru:
        ret += 1
    return ret


while True:
    y1, m1, d1, y2, m2, d2 = map(int, input().split())
    if min(y1, m1, d1, y2, m2, d2) < 0:
        quit()
    ymd1 = y_to_d(y1) + m_to_d(y1, m1) + d1
    ymd2 = y_to_d(y2) + m_to_d(y2, m2) + d2
    print(ymd2 - ymd1)

Python: M=[0,31,28,31,30,31,30,31,31,30,31,30]
def L(y,m):
  if m<=2: y-=1
  return y/4-y/100+y/400+sum(M[:m])
while 1:
  x=map(int,raw_input().split(" "))
  if x==[-1]*6: break
  a,b,c,d,e,f=x
  print (d-a)*365+f-c+L(d,e)-L(a,b)

Python: import datetime as D
while 1:
  a,b,c,d,e,f=x=map(int,raw_input().split(" "))
  try: print (D.date(d,e,f)-D.date(a,b,c)).days
  except: break

Python: # AOJ 0125 Day Count
# Python3 2018.6.18 bal4u

def ut2jd(year, month, day):
	if month <= 2:
		year -= 1
		month += 12
	s = 3 + year//4 - year//100 + year//400
	s += 1720994 + year*365 + (month+1)*30 + (month+1)*3//5 + day;
	return s

while True:
	y1, m1, d1, y2, m2, d2 = list(map(int, input().split()))
	if y1 < 0 or m1 < 0 or d1 < 0 or y2 < 0 or m2 < 0 or d2 < 0: break
	print(ut2jd(y2, m2, d2)-ut2jd(y1, m1, d1))

Python: def uru(y):
    return y % 4 == 0 and y % 100 != 0 or y % 400 == 0

def y_to_d(y):
    ret = 0
    for i in range(y):
        if uru(i):
            ret += 366
        else:
            ret += 365
    return ret

month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]


def m_to_d(y, m):
    m -= 1
    ret = 0
    for i in range(m-1):
        ret += month[i]
    if m >= 2 and uru:
        ret += 1
    return ret


while True:
    y1, m1, d1, y2, m2, d2 = map(int, input().split())
    if min(y1, m1, d1, y2, m2, d2) < 0:
        quit()
    ymd1 = y_to_d(y1) + m_to_d(y1, m1) + d1
    ymd2 = y_to_d(y2) + m_to_d(y2, m2) + d2
    print(ymd2 - ymd1)

Python: import datetime
while 1:
  a,b,c,d,e,f=map(int,raw_input().split(" "))
  if a==b==c==d==e==f==-1: break
  print (datetime.date(d,e,f)-datetime.date(a,b,c)).days

Python: import datetime
while True:
    y1, m1, d1, y2, m2, d2 = [int(x) for x in input().split()]
    if y1 < 0:
        break
    dt1 = datetime.date(y1,m1,d1)
    dt2 = datetime.date(y2,m2,d2)
    print((dt2-dt1).days)

Python: def y_to_d(y):
    y -= 1
    ret = 365 * y
    ret += y // 4
    ret -= y // 100
    ret += y // 400
    return ret

month = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]


def m_to_d(y, m):
    m -= 1
    ret = 0
    for i in range(m-1):
        ret += month[i]
    if m > 2 and (y % 4 == 0 and y % 100 != 0 or y % 400 == 0):
        ret += 1
    return ret


while True:
    y1, m1, d1, y2, m2, d2 = map(int, input().split())
    if y1 == m1 == d1 == y2 == m2 == d2 == -1:
        quit()
    ymd1 = y_to_d(y1) + m_to_d(y1, m1) + d1
    ymd2 = y_to_d(y2) + m_to_d(y2, m2) + d2
    print(ymd2 - ymd1)

Python: import datetime as D

while 1:
  a,b,c,d,e,f=x=map(int,raw_input().split(" "))
  if any([i<0 for i in x]): break
  print (D.date(d,e,f)-D.date(a,b,c)).days

Python: import datetime
while 1:
  x=map(int,raw_input().split(" "))
  if x==[-1]*6: break
  a,b,c,d,e,f=x
  print (datetime.date(d,e,f)-datetime.date(a,b,c)).days

Python: ans_list = []
days = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
while True:
    y1, m1, d1, y2, m2, d2 = map(int, input().split())
    if y1+y2+m1+m2+d1+d2 == -6:
        break
    else:
        ans = 0
        dis_m = m2 - m1
        dis_y = y2 - y1
        leap = 0
        if dis_y == 0:
            leap = 0
            if y1 % 4 == 0:
                if y1 % 100 == 0:
                    if y1 % 400 != 0:
                        leap = 1
                else:
                    leap = 1
            if dis_m == 0:
                ans = d2 - d1
            else:
                ans += sum(days[m1:m2-1]) + days[m1-1] - d1 + d2
            if leap == 1 and m1 < 3 and 2 < m2:
                ans += 1
            ans_list.append(ans)
        else:
            for y in range(y1, y2+1):
                leap = 0
                if y % 4 == 0:
                    if y % 100 == 0 and y % 400 != 0:
                        leap = 0
                    else:
                        leap = 1
                if y == y1:
                    ans += sum(days[m1:]) + days[m1-1] - d1
                    if leap == 1 and m1 < 3:
                        ans += 1
                elif y == y2:
                    ans += sum(days[:m2-1]) + d2
                    if leap == 1 and m2 > 2:
                        ans += 1
                else:
                    if leap == 0:
                        ans += 365
                    else:
                        ans += 366
            ans_list.append(ans)
for a in ans_list:
    print(a)

Python: def convert(y, m, d):
    if m <= 2:
        m += 12
        y -= 1
    mjd = int(365.25*y) + (y//400) - (y//100) + int(30.59*(m-2)) + d - 678912
    return mjd
while 1:
    y1, m1, d1, y2, m2, d2 = map(int, input().split())
    if y1 == -1:
        break
    print(convert(y2, m2, d2) - convert(y1, m1, d1))

Python: import datetime
while 1:
    y1,m1,d1,y2,m2,d2=map(int,input().split())
    if y1==-1:break
    d1 = datetime.date(y1, m1, d1)
    d2 = datetime.date(y2, m2, d2)
    print((d2-d1).days)

Python: import datetime
while 1:
    y1,m1,d1,y2,m2,d2=map(int,input().split())
    if y1==-1:break
    print((datetime.datetime(y2,m2,d2)-datetime.datetime(y1,m1,d1)).days)