tell me centure

#include<bits/stdc++.h>
using namespace std;
bool unique(string str)
{
    sort(str.begin(), str.end());
    for (int i = 0; i < str.length(); i++)
    {
        if (str[i] == str[i + 1])
        {
            return false;
        }
    }
    return true;
}
int main()
{
    long long int  i,j,k,m=0,l,n,o=0,p=0,x;
    map<char ,int> ma,mb;
    map<char ,int> ::iterator im;
    string s,c;
    cin>>x;
    for(i=1;i<=x;i++)
    {m=0;
        cin>>n;
        if(n%100==0)
        {
            m = n/100;
             k=m;
             k%=10;
             if(k==1&&(m>20 || m<10))
             {
                cout<<"Case #"<<i<<": "<<m<<"st century!"<<endl;
             }
             else if(k==2&&(m>20 || m<10))
             {
                cout<<"Case #"<<i<<": "<<m<<"nd century!"<<endl;
             }
             else if(k==3&&(m>20 || m<10))
             {
                cout<<"Case #"<<i<<": "<<m<<"rd century!"<<endl;
             }
             else
             {
                              cout<<"Case #"<<i<<": "<<m<<"th century!"<<endl;

             }
        }
        if(n%100 != 0)
        {
             m = n/100;
             k=m;
             k%=10;
             if(k+1==1&&(m>20 || m<10))
             {
                cout<<"Case #"<<i<<": "<<m+1<<"st century!"<<endl;
             }
              else if(k+1==2&&(m>20 || m<10))
             {
                cout<<"Case #"<<i<<": "<<m+1<<"nd century!"<<endl;
             }
             else if(k+1==3&&(m>20 || m<10))
             {
                cout<<"Case #"<<i<<": "<<m+1<<"rd century!"<<endl;
             }
             else
             {
                              cout<<"Case #"<<i<<": "<<m+1<<"th century!"<<endl;

             }
        }
    }



}