How many statements need to be changed to return the product instead of the sum?

Flowchart Main has no variables and $5$ nodes. Node $1$ is the start node and points to node $2.$ Node $2$ code: Put Calculate$(3,4)$ to output Node $2$ points to node $3.$ Node $3$ code: Put Calculate$(5,2)$ to output Node $3$ points to node $4.$ Node $4$ code: Put Calculate$(6,7)$ to output Node $4$ points to node $5.$ Node $5$ is the end node. Flowchart Calculate has $2$ parameter variables $($integer a$,$ integer b$),1$ return variable $($integer c$),$ and $3$ nodes. Node $1$ is the start node and points to node $2.$ Node $2$ code: c $=$ a $+$ b Node $2$ points to node $3.$ Node $3$ is the end node.

a$.$

$1$

b$.$

$2$

c$.$

$3$

d$.$

$4$