please, help me...
my code:

#include <iostream>

using namespace std;



int main()
{
    int n,m[16],k;
    char c[48][20],v[16][20],ch[3][20];
    cin>>n;
    for(int i=0;i<n*3;i++)
        cin>>c[i];
    for(int i=0;i<n;i++)
    {
        cin>>k;
        m[i]=k;
    }
    k=(m[0]-1)*3;
    if((strcmp(c[k],c[k+1])<=0)&&(strcmp(c[k],c[k+2])<=0)){strcpy(v[0],c[k]);}
    if((strcmp(c[k+1],c[k])<=0)&&(strcmp(c[k+1],c[k+2])<=0)){strcpy(v[0],c[k+1]);}
    if((strcmp(c[k+1],c[k])<=0)&&(strcmp(c[k+1],c[k+2])<=0)){strcpy(v[0],c[k+1]);}
    for(int i=1;i<n;i++)
    {
        k=(m[i]-1)*3;
        if((strcmp(c[k],c[k+1])<=0)&&(strcmp(c[k],c[k+2])<=0))
        {
            strcpy(ch[0],c[k]);
            if(strcmp(c[k+1],c[k+2])<=0)
            {
                strcpy(ch[1],c[k+1]);
                strcpy(ch[2],c[k+2]);
            }
            else
            {
                strcpy(ch[2],c[k+1]);
                strcpy(ch[1],c[k+2]);
            }
        }

            if((strcmp(c[k+1],c[k])<=0)&&(strcmp(c[k+1],c[k+2])<=0))
            {
                strcpy(ch[0],c[k+1]);
                if(strcmp(c[k],c[k+2])<=0)
                {
                    strcpy(ch[1],c[k]);
                    strcpy(ch[2],c[k+2]);
                }
                else
                {
                    strcpy(ch[2],c[k]);
                    strcpy(ch[1],c[k+2]);
                }
            }

                if((strcmp(c[k+2],c[k])<=0)&&(strcmp(c[k+2],c[k+1])<=0))
                {
                    strcpy(ch[0],c[k+2]);
                    if(strcmp(c[k],c[k+1])<=0)
                    {
                        strcpy(ch[1],c[k]);
                        strcpy(ch[2],c[k+1]);
                    }
                    else
                    {
                        strcpy(ch[2],c[k]);
                        strcpy(ch[1],c[k+1]);
                    }
                }

        if(strcmp(v[i-1],ch[0])<=0)
        {
            strcpy(v[i],ch[0]);
        }
        else
        {
            if(strcmp(v[i-1],ch[1])<=0)
            {
                strcpy(v[i],ch[1]);
            }
            else
            {
                if(strcmp(v[i-1],ch[2])<=0)
                {
                    strcpy(v[i],ch[2]);
                }
                else
                {
                    cout<<"IMPOSSIBLE";
                    return 0;
                }
            }
        }

    }
    for(int i=0;i<n;i++)
    {
        cout<<v[i]<<endl;
    }
    return 0;
}