#include <stdio.h>
int main(void) {
int a[34],i;
a[0]=2;
a[1]=-1;
for(i=0;i<32;i++){
a[i+2]= -a[i+1]+a[i]+2;
if(a[i+2]>5000){
break;
}
}
return 0;
}
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