b=1.
	a=0.
	n=1000
	dx=(b-a)/n
	sum=0.
	do i=1,n-1
	x=a+i*dx+dx/2.
	
	sum=sum+f(x)*dx
	enddo
	print*,sum
	stop
	end
	
	function f(x)
	f=x**2
	return
	end	
	
	
	real,allocatable:: a(:,:),b(:,:),c(:,:)
	
	open(10,file="test_3.in")
	read (10,*) n
	
	allocate (a(n,n),b(n,n),c(n,n))
	read (10,*)a ,b
		
	do i=1,n
	do j=1,n
	sum=0.
	
	do k=1,n
	sum=sum+a(i,k)*b(k,j)
	enddo
	c(i,j)=sum
	enddo
	enddo
	
	
	do i=1,n
	print '(100f10.5)',c(i,:)
	enddo
	
	stop
	end
		real,allocatable:: a(:)
	
	open(10,file="test_4.in")
	read (10,*)n
	allocate(a(n))
	read(10,*)a
	
	amax=-1.e32
	amin= 1.e32
	
	do i=1,n
	
	if(a(i).gt.amax)then
	amax=a(i)
	endif
	
	if(a(i).lt.amax)then
	amin=a(i)
	endif
	
	enddo
	print *,amin,amax
	
	stop
	end
	
		b=1.
	fb=f(b)
	n=10000000
	ns=0
	do i=1,n
	xj=rand(0)*b
	yj=rand(0)*fb
	y=f(xj)
	if(y.ge.yj)then
	ns=ns+1
	endif
	enddo
	
	print *,ns*b*fb/n
	stop

	end
	
	
	function f(x)
	f=x*x
	return
	end
		n=10000000
	
	ns=0
	do i=1,n
	xj=rand(0)
	yj=rand(0)
	
	if(yj**2+xj**2.le.1.)then
	ns=ns+1
	endif
	enddo
	
	print *,ns*4./n
	stop

	end
	
	
	function f(x)
	f=x*x
	return
	end
		pi=3.1415926536
	print *,"  x[rad]        x[grad]        sin         cos       tan"
	print *,"============================================================"
	do x=0.,pi/2.,0.01
	print '(5f12.4)',x,x*180/pi,sin(x),cos(x),tan(x)
	enddo
	
	stop
	end
		real,allocatable::a(:)
	
	open(10,file="test1.in")
	read (10,*) n
	allocate(a(n))
	read(10,*)a
	
	sum=0.
	do i=1,n
	sum=sum+a(i)
	enddo
	print *,sum
	stop
	end
	
	
	external func
        a=0.
        b=1.
        abserr=0.0000
        relerr=0.0000001
        call  quanc8(func,a,b,abserr,relerr,result,errest,nofun,flag)
	print *,result*4.,errest
	stop
	end
	function func(x)
	func=sqrt(abs(1.-x*x))
	return
	end
		read *,n
	nr=0
	do i=1,n
	x=rand()
	y=rand()
	if ((x*x+y*y).le.1)then
	nr=nr+1
	endif
	enddo
	print*,4.*nr/n
	stop
	end
		call srand(23)
	do i=1,10
	print *, rand()
	enddo
	stop
	end