Nine degrees 1035-tree-Find immediate family

At the beginning of this topic I thought it was a collection, and later found more simple than the collection, is a family tree, and then find the depth difference between two nodes.

#include <stdio.h>int data[30];     void Make_set () {for (int i=0;i<30;i++) data[i]=-1;} int find (int a,int b) {int re=1;        while (Data[a]!=-1) {if (data[a]==b) return re;        A=data[a];        re++; } return-1;}    int main () {int n,m;    Char a[4];        while (scanf ("%d%d", &n,&m)} {if (m==0&&n==0) break;        Make_set ();            for (int i=0;i<n;i++) {scanf ("%s", a);        data[a[1]-' A ']=data[a[2]-' a ']=a[0]-' a ';            } for (int i=0;i<m;i++) {scanf ("%s", a);            int X=find (a[0]-' A ', a[1]-' a ');            int Y=find (a[1]-' A ', a[0]-' a ');            int re = x>y?x:y;            if (re<=0) {printf ("-\n");                } else{if (x>0) {if (re==1) printf ("parent\n");                    else{for (int i=2;i<re;i++) {printf ("great-");      }              printf ("grandparent\n");                }} else if (y>0) {if (re==1) printf ("child\n");                    else{for (int i=2;i<re;i++) {printf ("great-");                } printf ("grandchild\n"); }}}}} return 0;}

Nine degrees 1035-tree-Find immediate family