Language: C

char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}

Compiler output:
main.c:1:18: warning: data definition has no type or storage class
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                  ^
main.c:1:18: error: type defaults to 'int' in declaration of 'n' [-Wimplicit-int]
main.c:1:20: error: type defaults to 'int' in declaration of 'm' [-Wimplicit-int]
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                    ^
main.c:1:22: error: type defaults to 'int' in declaration of 'i' [-Wimplicit-int]
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                      ^
main.c:1:24: error: type defaults to 'int' in declaration of 'c' [-Wimplicit-int]
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                        ^
main.c:1:26: error: type defaults to 'int' in declaration of 'p' [-Wimplicit-int]
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                          ^
main.c:1:28: error: return type defaults to 'int' [-Wimplicit-int]
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                            ^~~~
main.c: In function 'main':
main.c:1:28: error: type of 's' defaults to 'int' [-Wimplicit-int]
main.c:1:43: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                                           ^~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
main.c:1:43: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                                           ^~~~~
main.c:1:43: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:1:80: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                                                                                ^~~~~~
main.c:1:80: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:80: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
main.c:1:80: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:151: error: invalid type argument of unary '*' (have 'int')
    1 | char*z,a[2][204];n,m,i,c,p;main(s){for(;m=scanf("%d %[^\n] %[^\n]",&n,a,a+1)*n;printf(m>n?"NA\n":"%d\n",m))for(i=2;i--;m=c)for(c=p=0;z=p+p+a[c+i&1],s=*p,c<m&&!s|n+~p;)p+=p<n&&s?~s|z[2]-49?++c,2:1:-1;}
      |                                                                                                                                                       ^~