Language: C

a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}

Compiler output:
main.c:1:1: warning: data definition has no type or storage class
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      | ^
main.c:1:1: error: type defaults to 'int' in declaration of 'a' [-Wimplicit-int]
main.c:1:7: error: type defaults to 'int' in declaration of 'i' [-Wimplicit-int]
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |       ^
main.c:1:9: error: type defaults to 'int' in declaration of 'x' [-Wimplicit-int]
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |         ^
main.c:1:11: error: type defaults to 'int' in declaration of 'n' [-Wimplicit-int]
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |           ^
main.c:1:13: error: type defaults to 'int' in declaration of 'm' [-Wimplicit-int]
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |             ^
main.c:1:15: error: type defaults to 'int' in declaration of 'k' [-Wimplicit-int]
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |               ^
main.c:1:17: error: return type defaults to 'int' [-Wimplicit-int]
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |                 ^~~~
main.c: In function 'main':
main.c:1:28: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |                            ^~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
main.c:1:28: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |                            ^~~~~
main.c:1:28: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:1:77: error: expected expression before ';' token
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |                                                                             ^
main.c:1:132: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    1 | a[50],i,x,n,m,k;main(){for(scanf("%d%d",&n,&m);i<n;i++)for(scanf("%d",&k);k-;a[x]++)scanf("%d",&x);for(i=m,x=0;i--;)if(a[i]==n)x++;printf("%d\n",x);}
      |                                                                                                                                    ^~~~~~
main.c:1:132: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:132: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
main.c:1:132: note: include '<stdio.h>' or provide a declaration of 'printf'