program example
	implicit none

	integer(8) N,A,B,amari
    
    read(*,*)N,A,B
    
    if(A==0) then
    	write(*,*)"0"
    else
    	if(N/(A+B)==0) then
        	write(*,*) A
        else
    		amari=mod(N,A+B)
            
        	if(amari<=A) then
        		write(*,*) (N*A/(A+B))+amari
        	else
        		write(*,*) (N*A/(A+B))+A
        	end if
    	end if
    end if
end program example