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

#define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);})
#define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define WTHI(v) {unsigned _z=v,_n=0;long _d=0;while(++_n,_d=_d<<8|0x30|_z%10,_z/=10);*(long*)wp=_d;wp+=_n;}
#define WTLO(v) {unsigned _z=v,_n=8;long _d=0;while(_d=_d<<8|0x30|_z%10,_z/=10,--_n);*(long*)wp=_d;wp+=8;}
#define wt(v) ({ulong _v=v;if(_v>=100000000){if(_v>=10000000000000000l){WTHI(_v/10000000000000000l);WTLO(_v/100000000%100000000);}else WTHI(_v/100000000);WTLO(_v%100000000);}else{WTHI(_v);}})

typedef unsigned long ulong;

char wbuf[1<<25];

inline int is_coprime(int a,int b){
	if(!((a|b)&1)) return 0;
	a>>=__builtin_ctz(a);
	b>>=__builtin_ctz(b);
	int c;
	while(c=a-b){
		c>>=__builtin_ctz(c);
		if(c<0){
			b=-c;
		}else{
			a=c;
		}
	}
	return a==1;
}

int main(){
	char*wp=wbuf;
	rd_init();
	for(int q=rd();q--;){
		int x=rd();
		int n=rd();
		int d=rd();
		if(is_coprime(x,d)){
			if(x==1){
				*wp++='-';
				*wp++='1';
			}else{
				wt((ulong)x*((unsigned)(x-2)/(unsigned)n+d)-d);
			}
		}else{
			*wp++='i';
			*wp++='n';
			*wp++='f';
		}
		*wp++='\n';
	}
	write(1,wbuf,wp-wbuf);
	_exit(0);
}