Buggy python submission (verdict: Runtime Error):
import heapq
import copy
n = int(input())

size = 2*10**5
def f(ary):
    t_ans = 10**100
    for i in range(len(ary)):
        t_ud = ary[i]
        if len(t_ud) != 0:
            #print(t_ud)
            t_ud.sort()
            t_u = -10**100
            for j in range(len(t_ud)):
                if t_ud[j][1] == 'U':
                    t_u = t_ud[j][0]
                elif t_u == -10**100:
                    continue
                else:
                    t_ans = min(t_ans, (t_ud[j][0] - t_u))
    return t_ans

xyu = []

for i in range(n):
    x,y,u = input().split()
    x = int(x)
    y = int(y)
    xyu.append([x,y,u])

ud = [[] for i in range(size)]
rl = [[] for i in range(size)]
ul = [[] for i in range(size*2+2)]
ur = [[] for i in range(size*2+2)]
dl = [[] for i in range(size*2+2)]
dr = [[] for i in range(size*2+2)]

for i in range(n):
    if xyu[i][2] == 'U':
        ud[xyu[i][0]].append([xyu[i][1],'U'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'U'])
    if xyu[i][2] == 'D':
        ud[xyu[i][0]].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
    if xyu[i][2] == 'R':
        rl[xyu[i][0]].append([xyu[i][1],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
    if xyu[i][2] == 'L':
        rl[xyu[i][0]].append([xyu[i][1],'D'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'U'])
                  
ans = 10**100
ans = min(ans,f(ud)*5)
ans = min(ans,f(rl)*5)
ans = min(ans,f(ul)*10)
ans = min(ans,f(ur)*10)
ans = min(ans,f(dl)*10)
ans = min(ans,f(dr)*10)
if ans == 10**100:
    print('SAFE')
else:
    print(ans)

Fixed submission:
import heapq
import copy
n = int(input())

size = 2*10**5
def f(ary):
    t_ans = 10**100
    for i in range(len(ary)):
        t_ud = ary[i]
        if len(t_ud) != 0:
            #print(t_ud)
            t_ud.sort()
            t_u = -10**100
            for j in range(len(t_ud)):
                if t_ud[j][1] == 'U':
                    t_u = t_ud[j][0]
                elif t_u == -10**100:
                    continue
                else:
                    t_ans = min(t_ans, (t_ud[j][0] - t_u))
    return t_ans

xyu = []

for i in range(n):
    x,y,u = input().split()
    x = int(x)
    y = int(y)
    xyu.append([x,y,u])

ud = [[] for i in range(size+1)]
rl = [[] for i in range(size+1)]
ul = [[] for i in range(size*2+2)]
ur = [[] for i in range(size*2+2)]
dl = [[] for i in range(size*2+2)]
dr = [[] for i in range(size*2+2)]

for i in range(n):
    if xyu[i][2] == 'U':
        ud[xyu[i][0]].append([xyu[i][1],'U'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'U'])
    if xyu[i][2] == 'D':
        ud[xyu[i][0]].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
    if xyu[i][2] == 'R':
        rl[xyu[i][1]].append([xyu[i][0],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
    if xyu[i][2] == 'L':
        rl[xyu[i][1]].append([xyu[i][0],'D'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'U'])
                  
ans = 10**100
ans = min(ans,f(ud)*5)
ans = min(ans,f(rl)*5)
ans = min(ans,f(ul)*10)
ans = min(ans,f(ur)*10)
ans = min(ans,f(dl)*10)
ans = min(ans,f(dr)*10)
if ans == 10**100:
    print('SAFE')
else:
    print(ans)

Buggy python submission (verdict: Runtime Error):
import heapq
import copy
n = int(input())

size = 2*10**5
def f(ary):
    t_ans = 10**100
    for i in range(len(ary)):
        t_ud = ary[i]
        if len(t_ud) != 0:
            #print(t_ud)
            t_ud.sort()
            t_u = -10**100
            for j in range(len(t_ud)):
                if t_ud[j][1] == 'U':
                    t_u = t_ud[j][0]
                elif t_u == -10**100:
                    continue
                else:
                    t_ans = min(t_ans, (t_ud[j][0] - t_u))
    return t_ans

xyu = []

for i in range(n):
    x,y,u = input().split()
    x = int(x)
    y = int(y)
    xyu.append([x,y,u])

ud = [[] for i in range(size)]
rl = [[] for i in range(size)]
ul = [[] for i in range(size*2+2)]
ur = [[] for i in range(size*2+2)]
dl = [[] for i in range(size*2+2)]
dr = [[] for i in range(size*2+2)]

for i in range(n):
    if xyu[i][2] == 'U':
        ud[xyu[i][0]].append([xyu[i][1],'U'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'U'])
    if xyu[i][2] == 'D':
        ud[xyu[i][0]].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
    if xyu[i][2] == 'R':
        rl[xyu[i][0]].append([xyu[i][1],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]].append([xyu[i][1],'U'])
    if xyu[i][2] == 'L':
        rl[xyu[i][0]].append([xyu[i][1],'D'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'U'])
                  
ans = 10**100
ans = min(ans,f(ud)*5)
ans = min(ans,f(rl)*5)
ans = min(ans,f(ul)*10)
ans = min(ans,f(ur)*10)
ans = min(ans,f(dl)*10)
ans = min(ans,f(dr)*10)
if ans == 10**100:
    print('SAFE')
else:
    print(ans)

Fixed submission:
import heapq
import copy
n = int(input())

size = 2*10**5
def f(ary):
    t_ans = 10**100
    for i in range(len(ary)):
        t_ud = ary[i]
        if len(t_ud) != 0:
            #print(t_ud)
            t_ud.sort()
            t_u = -10**100
            for j in range(len(t_ud)):
                if t_ud[j][1] == 'U':
                    t_u = t_ud[j][0]
                elif t_u == -10**100:
                    continue
                else:
                    t_ans = min(t_ans, (t_ud[j][0] - t_u))
    return t_ans

xyu = []

for i in range(n):
    x,y,u = input().split()
    x = int(x)
    y = int(y)
    xyu.append([x,y,u])

ud = [[] for i in range(size+1)]
rl = [[] for i in range(size+1)]
ul = [[] for i in range(size*2+2)]
ur = [[] for i in range(size*2+2)]
dl = [[] for i in range(size*2+2)]
dr = [[] for i in range(size*2+2)]

for i in range(n):
    if xyu[i][2] == 'U':
        ud[xyu[i][0]].append([xyu[i][1],'U'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'U'])
    if xyu[i][2] == 'D':
        ud[xyu[i][0]].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
    if xyu[i][2] == 'R':
        rl[xyu[i][1]].append([xyu[i][0],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
    if xyu[i][2] == 'L':
        rl[xyu[i][1]].append([xyu[i][0],'D'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'U'])
                  
ans = 10**100
ans = min(ans,f(ud)*5)
ans = min(ans,f(rl)*5)
ans = min(ans,f(ul)*10)
ans = min(ans,f(ur)*10)
ans = min(ans,f(dl)*10)
ans = min(ans,f(dr)*10)
if ans == 10**100:
    print('SAFE')
else:
    print(ans)

Buggy python submission (verdict: Runtime Error):
import heapq
import copy
n = int(input())

size = 2*10**5
def f(ary):
    t_ans = 10**100
    for i in range(len(ary)):
        t_ud = ary[i]
        if len(t_ud) != 0:
            #print(t_ud)
            t_ud.sort()
            t_u = -10**100
            for j in range(len(t_ud)):
                if t_ud[j][1] == 'U':
                    t_u = t_ud[j][0]
                elif t_u == -10**100:
                    continue
                else:
                    t_ans = min(t_ans, (t_ud[j][0] - t_u))
    return t_ans

xyu = []

for i in range(n):
    x,y,u = input().split()
    x = int(x)
    y = int(y)
    xyu.append([x,y,u])

ud = [[] for i in range(size)]
rl = [[] for i in range(size)]
ul = [[] for i in range(size*2+2)]
ur = [[] for i in range(size*2+2)]
dl = [[] for i in range(size*2+2)]
dr = [[] for i in range(size*2+2)]

for i in range(n):
    if xyu[i][2] == 'U':
        ud[xyu[i][0]].append([xyu[i][1],'U'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'U'])
    if xyu[i][2] == 'D':
        ud[xyu[i][0]].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]].append([xyu[i][1],'D'])
    if xyu[i][2] == 'R':
        rl[xyu[i][0]].append([xyu[i][1],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]].append([xyu[i][1],'U'])
    if xyu[i][2] == 'L':
        rl[xyu[i][0]].append([xyu[i][1],'D'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'U'])
                  
ans = 10**100
ans = min(ans,f(ud)*5)
ans = min(ans,f(rl)*5)
ans = min(ans,f(ul)*10)
ans = min(ans,f(ur)*10)
ans = min(ans,f(dl)*10)
ans = min(ans,f(dr)*10)
if ans == 10**100:
    print('SAFE')
else:
    print(ans)

Fixed submission:
import heapq
import copy
n = int(input())

size = 2*10**5
def f(ary):
    t_ans = 10**100
    for i in range(len(ary)):
        t_ud = ary[i]
        if len(t_ud) != 0:
            #print(t_ud)
            t_ud.sort()
            t_u = -10**100
            for j in range(len(t_ud)):
                if t_ud[j][1] == 'U':
                    t_u = t_ud[j][0]
                elif t_u == -10**100:
                    continue
                else:
                    t_ans = min(t_ans, (t_ud[j][0] - t_u))
    return t_ans

xyu = []

for i in range(n):
    x,y,u = input().split()
    x = int(x)
    y = int(y)
    xyu.append([x,y,u])

ud = [[] for i in range(size+1)]
rl = [[] for i in range(size+1)]
ul = [[] for i in range(size*2+2)]
ur = [[] for i in range(size*2+2)]
dl = [[] for i in range(size*2+2)]
dr = [[] for i in range(size*2+2)]

for i in range(n):
    if xyu[i][2] == 'U':
        ud[xyu[i][0]].append([xyu[i][1],'U'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'U'])
    if xyu[i][2] == 'D':
        ud[xyu[i][0]].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
    if xyu[i][2] == 'R':
        rl[xyu[i][1]].append([xyu[i][0],'U'])
        ur[xyu[i][1]+xyu[i][0]].append([xyu[i][1],'D'])
        dr[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'U'])
    if xyu[i][2] == 'L':
        rl[xyu[i][1]].append([xyu[i][0],'D'])
        ul[xyu[i][1]-xyu[i][0]+size].append([xyu[i][1],'D'])
        dl[xyu[i][0]+xyu[i][1]].append([xyu[i][1],'U'])
                  
ans = 10**100
ans = min(ans,f(ud)*5)
ans = min(ans,f(rl)*5)
ans = min(ans,f(ul)*10)
ans = min(ans,f(ur)*10)
ans = min(ans,f(dl)*10)
ans = min(ans,f(dr)*10)
if ans == 10**100:
    print('SAFE')
else:
    print(ans)