#include <bits/stdc++.h> using namespace std; int main(){ char s[100005]; cin>>s; for(int i=0;i<strlen(s);i++){ int flag=0; for(int j=0;j<strlen(s);j++){ if(s[j]s[i] && i!=j) flag=1; } if(flag0){ cout<<s[i]; return 0; } } cout<<"no"; return 0; }

include <bits/stdc++.h> using namespace std; const int N = 100001; int n,a[N]; string s; int main(){ cin>>s; for(auto i:s){ a[ i-'a'] ++; } for(int i=0;i<=26;++i){ if(a[i]==1){ cout<<char(i+'a'); return 0; } } cout<<"no"; return 0; }

#include<bits/stdc++.h> using namespace std; char s[100000]; int a[26],b=0; int main(){ cin>>s; int n = strlen(s); for(int j=0;j<n;j++){ for(int i=0;i<26;i++)if(s[j]==char('a'+i))a[i]; } for(int i=0;i<26;i){if(a[i]1){cout<<char('a'+i);b=1;break;}} if(b0)cout<<"no"; return 0; }

python: a = input() for i in a: if a.count(i) == 1: print(i) break else: print('no')

e = input() de = {} for i in e: if i not in de: de[i] = 1 else: de[i]+=1 for i in de: if de[i] == 1: print(i) break else: print("no")