length of longest subsequence(easy zoho)

#include <iostream>
using namespace std;

int main() {
    int i,j,out=-1;
    char s[100];
    cin>>s;
    int size=0;
    for(i=0;s[i]!='\0';i++)
      {
          size++;
      }
    i=0;
    j=size-1;
    
    for(i=0;i<size-1;i++)
    {
        for(j=i+1;j<size;j++)
         {
              if(s[i]==s[j]&&(j-i-1)>out)
               out=j-i-1;
         }
         
    }
    cout<<out;
    return 0;
}