OJ Board

I got WA.
But, I don't know what's wrong.
Could you help me??
Thx.


#include <stdio.h>
#define NUM 51
int v[NUM][NUM];

void eulercycle(int x){
int i;
for( i=1; i<NUM; i++){
if(v[x][i]!=0){

--v[x][i];
--v[i][x];
printf("%d %d\n", x, i);
eulercycle(i);
}
}
}
int main(){
int casenum, n ...