Swapping letters

# -*- coding: utf-8 -*-
"""
Created on Sat Sep 15 15:46:11 2018

@author: kiyakf1
"""

def function():
    
    n = int(raw_input())
    pairs = []
    
    for i in range(n):
        pairs.append(raw_input().split(" "))

    x = list(raw_input())
    y = list(raw_input())
    
    
    
    def pairmap(string, pairs):
        pairmap = []
        for i in range(len(pairs)):
            pairmap.append([0])
        
        for x in string:
            for i in range(len(pairs)):
                if x == pairs[i][0]:
                    if len(pairmap[i])% 2 == 0:
                        pairmap[i].append(1)
                    else:
                        pairmap[i][len(pairmap[i])-1]+=1
                if x == pairs[i][1]:
                    if len(pairmap[i])% 2 == 0:
                        pairmap[i][len(pairmap[i])-1]+=1
                    else:
                        pairmap[i].append(1)
                    
        return pairmap
                    
                    
    for mapx,mapy in zip(pairmap(x,pairs),pairmap(y,pairs)):
        if(mapx != mapy):
            return "NO"
            
    return "YES"
        
        
print function()

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: TIME LIMIT EXCEEDED

Test 5

Verdict: TIME LIMIT EXCEEDED

Test 6

Verdict: TIME LIMIT EXCEEDED

Test 7

Verdict: TIME LIMIT EXCEEDED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: WRONG ANSWER

Test 10

Verdict: WRONG ANSWER