Thread: terminate loop

Having problem in terminating my loop. Any help would be good

int main(void)
{
int num=0, signal=0;

while(signal<100)
{
scanf("%d", &signal);
{
if (signal>7)
{
printf("During minutes %d, traffic flow is %d vehicles per minute\n", num, signal);
}
num++;
}
}
return (0);
}