Wave equation using dirchlet boundary conditions

Utt means second derivative with respect to t
Uxx means second derivative with respect to x
The answer must meet all of the Boundary and other conditions.
Solve:
Utt = Uxx,    0 < x < pi,    t > 0

U(0,t) = 0,  U(pi,t) = 0

U(x,0) = 0,  Ut(x,0) = 1  for 0 < x < pi

The solution should be in an infinite sum.