#include <stdio.h>

const int MX=500001;
int A[MX];
unsigned char P[MX][3];
int H[1001];
int n,o,i,q,w;
char c;
main()
{

    scanf("%d",&n);
    scanf("%c",&c);
    o=0;
    while (n>0)
    {
        scanf("%c%c",&c,&c);
        if(c=='U')
        {
            scanf("SH %d %d",&q,&w);
            if (o+1>=MX)
            {
                for (i=0; i<o; i++) if (A[i]<0) break;
            }
            else
            {
                o++;
                i=o;
            }
            A[i]=w;
            P[i][0]=H[q] / (256*256); H[q]%=(256*256);
            P[i][1]=H[q] / (256); H[q]%=256;
            P[i][2]=H[q];
            H[q]=i;
            scanf("%c",&c);
        }
        else
        {
            scanf("P %d",&q);
            printf("%ld\n",A[H[q]]);
            A[H[q]]=-1;
            H[q]=(int)P[H[q]][0]*256*256+(int)P[H[q]][1]*256+(int)P[H[q]][2];
            scanf("%c",&c);
        }
        n--;
    }
}

Hmm... Dev-C++ compile this code.
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