src.c: In function 'max':
src.c:15:4: error: 'x' undeclared (first use in this function)
if(x>y)m=x;
^
src.c:15:4: note: each undeclared identifier is reported only once for each function it appears in
src.c:15:6: error: 'y' undeclared (first use in this function)
if(x>y)m=x;
^
src.c:17:6: error: 'z' undeclared (first use in this function)
if(m>z)n=m;
^