#include <stdio.h>
#include <string.h>
#include <stdbool.h>

bool solution(char* s1, char* s2) {
    int len1 = strlen(s1);
    int len2 = strlen(s2);
    
    if (len1 != len2) {
        return false;
    }
    
    // Check if both strings have same character frequencies
    int freq1[26] = {0};
    int freq2[26] = {0};
    
    for (int i = 0; i < len1; i++) {
        freq1[s1[i] - 'a']++;
        freq2[s2[i] - 'a']++;
    }
    
    for (int i = 0; i < 26; i++) {
        if (freq1[i] != freq2[i]) {
            return false;
        }
    }
    
    // Find positions where characters differ
    int diffPositions[1000];
    int diffCount = 0;
    
    for (int i = 0; i < len1; i++) {
        if (s1[i] != s2[i]) {
            diffPositions[diffCount++] = i;
        }
    }
    
    // Can make equal if 0 differences or exactly 2 differences that can be swapped
    if (diffCount == 0) {
        return true;
    } else if (diffCount == 2) {
        int i = diffPositions[0];
        int j = diffPositions[1];
        return s1[i] == s2[j] && s1[j] == s2[i];
    } else {
        return false;
    }
}

int main() {
    char s1[1001], s2[1001];
    fgets(s1, sizeof(s1), stdin);
    fgets(s2, sizeof(s2), stdin);
    s1[strcspn(s1, "\n")] = 0;
    s2[strcspn(s2, "\n")] = 0;
    
    bool result = solution(s1, s2);
    printf(result ? "true\n" : "false\n");
    return 0;
}