#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

char*mmap();
#define RD(v) long v=0;{int _c;while(_c=*rp++-48,_c>=0)v=v*10+_c;}

#define WTHI(v) {long _z=v,_n=0,_d=0;while(++_n,_d=_d<<8|0x30|_z%10,_z/=10);*(long*)wp=_d;wp+=_n;}
#define WTLO(v) {long _z=v,_n=8,_d=0;while(_d=_d<<8|0x30|_z%10,_z/=10,--_n);*(long*)wp=_d;wp+=8;}
#define WT(v) if(v>=100000000){if(v>=10000000000000000l){WTHI(v/10000000000000000l);WTLO(v/100000000);}else WTHI(v/100000000);WTLO(v);}else{WTHI(v);}

main(){
	char wbuf[20*2000];
	char*wp=wbuf;
	char*rp=mmap(0l,1l<<28,1,2,0,0ll);
	while(*rp++!=10);
	do{
		RD(d);
		RD(a);
		RD(b);
		a-=!!a;
		--d;
		long z=(a/d-b/d)*d*~d;
		a%=d;
		b%=d;
		z+=~(a%=d)*a-~(b%=d)*b;
		z>>=1;
		WT(z);
		*wp++=10;
	}while(*rp);
	write(1,wbuf,wp-wbuf);
	_exit(0);
}