Buggy python submission (verdict: Runtime Error):
from math import ceil,floor,comb,factorial,gcd,pow,sqrt,log2,cos,sin,tan,pi,inf
from itertools import accumulate,permutations,combinations,product,combinations_with_replacement
from collections import deque,defaultdict,Counter
from bisect import bisect_left,bisect_right
from operator import itemgetter
from heapq import heappop,heappush
from copy import deepcopy
from time import time
import string
import sys
sys.setrecursionlimit(10 ** 7)
def input() : return sys.stdin.readline().strip()
def INT()   : return int(input())
def MAP()   : return map(int,input().split())
def LIST()  : return list(MAP())

n, m = MAP()
ans = [-1]*n

for i in range(m):
    s, c = MAP()
    s -= 1
    if ans[s] == -1 or ans[s] == c:
        ans[s] = c
    else:
        print(-1)
        exit()

if n != 1 and ans[0] == 0:
    print(-1)
    exit()
else:
    for i in range(m):
        if ans[i] == -1:
            if n != 1 and i == 0:
                ans[i] = 1
            else:
                ans[i] = 0
    print(*ans, sep='')

Fixed submission:
from math import ceil,floor,comb,factorial,gcd,pow,sqrt,log2,cos,sin,tan,pi,inf
from itertools import accumulate,permutations,combinations,product,combinations_with_replacement
from collections import deque,defaultdict,Counter
from bisect import bisect_left,bisect_right
from operator import itemgetter
from heapq import heappop,heappush
from copy import deepcopy
from time import time
import string
import sys
sys.setrecursionlimit(10 ** 7)
def input() : return sys.stdin.readline().strip()
def INT()   : return int(input())
def MAP()   : return map(int,input().split())
def LIST()  : return list(MAP())

n, m = MAP()
ans = [-1]*n

for i in range(m):
    s, c = MAP()
    s -= 1
    if ans[s] == -1 or ans[s] == c:
        ans[s] = c
    else:
        print(-1)
        exit()

if ans[0] == 0:
    if n == 1:
        print(0)
    else:
        print(-1)
    exit()
else:
    for i in range(n):
        if ans[i] == -1:
            if n != 1 and i == 0:
                ans[i] = 1
            else:
                ans[i] = 0
    print(*ans, sep='')

Buggy python submission (verdict: Runtime Error):
from math import ceil,floor,comb,factorial,gcd,pow,sqrt,log2,cos,sin,tan,pi,inf
from itertools import accumulate,permutations,combinations,product,combinations_with_replacement
from collections import deque,defaultdict,Counter
from bisect import bisect_left,bisect_right
from operator import itemgetter
from heapq import heappop,heappush
from copy import deepcopy
from time import time
import string
import sys
sys.setrecursionlimit(10 ** 7)
def input() : return sys.stdin.readline().strip()
def INT()   : return int(input())
def MAP()   : return map(int,input().split())
def LIST()  : return list(MAP())

n, m = MAP()
ans = [-1]*n

for i in range(m):
    s, c = MAP()
    s -= 1
    if ans[s] == -1 or ans[s] == c:
        ans[s] = c
    else:
        print(-1)
        exit()

if n != 1 and ans[0] == 0:
    print(-1)
    exit()
else:
    for i in range(m):
        if ans[i] == -1:
            if i == 0:
                ans[i] = 1
            else:
                ans[i] = 0
    print(*ans,sep='')

Fixed submission:
from math import ceil,floor,comb,factorial,gcd,pow,sqrt,log2,cos,sin,tan,pi,inf
from itertools import accumulate,permutations,combinations,product,combinations_with_replacement
from collections import deque,defaultdict,Counter
from bisect import bisect_left,bisect_right
from operator import itemgetter
from heapq import heappop,heappush
from copy import deepcopy
from time import time
import string
import sys
sys.setrecursionlimit(10 ** 7)
def input() : return sys.stdin.readline().strip()
def INT()   : return int(input())
def MAP()   : return map(int,input().split())
def LIST()  : return list(MAP())

n, m = MAP()
ans = [-1]*n

for i in range(m):
    s, c = MAP()
    s -= 1
    if ans[s] == -1 or ans[s] == c:
        ans[s] = c
    else:
        print(-1)
        exit()

if ans[0] == 0:
    if n == 1:
        print(0)
    else:
        print(-1)
    exit()
else:
    for i in range(n):
        if ans[i] == -1:
            if n != 1 and i == 0:
                ans[i] = 1
            else:
                ans[i] = 0
    print(*ans, sep='')

Buggy python submission (verdict: Runtime Error):
n, m = map(int, input().split())
s = [0]*m
c = [0]*m
num = ['']*n
for i in range(m):
    s[i], c[i] = map(int, input().split())
    if s[i]==1 and c[i]==0:
        print(-1)
        exit()
    elif num[s[i]-1] == '':
        num[s[i]-1] = c[i]
    elif num[s[i]-1] != c[i]:
        print(-1)
        exit()
for i in range(m):
    if num[i]=='':
        if i == 0:
            num[i] = 1
        else:
            num[i] = 0
print(''.join(map(str,num)))

Fixed submission:
from math import ceil,floor,comb,factorial,gcd,pow,sqrt,log2,cos,sin,tan,pi,inf
from itertools import accumulate,permutations,combinations,product,combinations_with_replacement
from collections import deque,defaultdict,Counter
from bisect import bisect_left,bisect_right
from operator import itemgetter
from heapq import heappop,heappush
from copy import deepcopy
from time import time
import string
import sys
sys.setrecursionlimit(10 ** 7)
def input() : return sys.stdin.readline().strip()
def INT()   : return int(input())
def MAP()   : return map(int,input().split())
def LIST()  : return list(MAP())

n, m = MAP()
ans = [-1]*n

for i in range(m):
    s, c = MAP()
    s -= 1
    if ans[s] == -1 or ans[s] == c:
        ans[s] = c
    else:
        print(-1)
        exit()

if ans[0] == 0:
    if n == 1:
        print(0)
    else:
        print(-1)
    exit()
else:
    for i in range(n):
        if ans[i] == -1:
            if n != 1 and i == 0:
                ans[i] = 1
            else:
                ans[i] = 0
    print(*ans, sep='')

Buggy python submission (verdict: Runtime Error):
n, m = map(int, input().split())
s = [0]*m
c = [0]*m
num = ['']*n
for i in range(m):
    s[i], c[i] = map(int, input().split())
    if s[i]==1 and c[i]==0:
        print(-1)
        exit()
    elif num[s[i]-1] == '':
        num[s[i]-1] = c[i]
    elif num[s[i]-1] != c[i]:
        print(-1)
        exit()
for i in range(m):
    if num[i]=='':
        num[i] = 1
print(''.join(map(str,num)), end="")

Fixed submission:
from math import ceil,floor,comb,factorial,gcd,pow,sqrt,log2,cos,sin,tan,pi,inf
from itertools import accumulate,permutations,combinations,product,combinations_with_replacement
from collections import deque,defaultdict,Counter
from bisect import bisect_left,bisect_right
from operator import itemgetter
from heapq import heappop,heappush
from copy import deepcopy
from time import time
import string
import sys
sys.setrecursionlimit(10 ** 7)
def input() : return sys.stdin.readline().strip()
def INT()   : return int(input())
def MAP()   : return map(int,input().split())
def LIST()  : return list(MAP())

n, m = MAP()
ans = [-1]*n

for i in range(m):
    s, c = MAP()
    s -= 1
    if ans[s] == -1 or ans[s] == c:
        ans[s] = c
    else:
        print(-1)
        exit()

if ans[0] == 0:
    if n == 1:
        print(0)
    else:
        print(-1)
    exit()
else:
    for i in range(n):
        if ans[i] == -1:
            if n != 1 and i == 0:
                ans[i] = 1
            else:
                ans[i] = 0
    print(*ans, sep='')

Buggy python submission (verdict: Runtime Error):
n, m = map(int, input().split())
s = [0]*m
c = [0]*m
num = ['']*n
for i in range(m):
    s[i], c[i] = map(int, input().split())
    if s[i]==1 and c[i]==0:
        print(-1)
        exit()
    elif num[s[i]-1] == '':
        num[s[i]-1] = c[i]
    elif num[s[i]-1] != c[i]:
        print(-1)
        exit()
for i in range(m):
    if num[i]=='':
        num[i] = 1
print(''.join(map(str,num)))

Fixed submission:
from math import ceil,floor,comb,factorial,gcd,pow,sqrt,log2,cos,sin,tan,pi,inf
from itertools import accumulate,permutations,combinations,product,combinations_with_replacement
from collections import deque,defaultdict,Counter
from bisect import bisect_left,bisect_right
from operator import itemgetter
from heapq import heappop,heappush
from copy import deepcopy
from time import time
import string
import sys
sys.setrecursionlimit(10 ** 7)
def input() : return sys.stdin.readline().strip()
def INT()   : return int(input())
def MAP()   : return map(int,input().split())
def LIST()  : return list(MAP())

n, m = MAP()
ans = [-1]*n

for i in range(m):
    s, c = MAP()
    s -= 1
    if ans[s] == -1 or ans[s] == c:
        ans[s] = c
    else:
        print(-1)
        exit()

if ans[0] == 0:
    if n == 1:
        print(0)
    else:
        print(-1)
    exit()
else:
    for i in range(n):
        if ans[i] == -1:
            if n != 1 and i == 0:
                ans[i] = 1
            else:
                ans[i] = 0
    print(*ans, sep='')