Language: C

a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}

Compiler output:
main.c:1:1: warning: data definition has no type or storage class
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      | ^
main.c:1:1: error: type defaults to 'int' in declaration of 'a' [-Wimplicit-int]
main.c:1:3: error: type defaults to 'int' in declaration of 'b' [-Wimplicit-int]
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      |   ^
main.c:1:5: error: type defaults to 'int' in declaration of 'i' [-Wimplicit-int]
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      |     ^
main.c:1:7: error: type defaults to 'int' in declaration of 't' [-Wimplicit-int]
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      |       ^
main.c:1:23: error: return type defaults to 'int' [-Wimplicit-int]
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      |                       ^
main.c: In function 'L':
main.c:1:23: error: type of 'x' defaults to 'int' [-Wimplicit-int]
main.c:1:23: error: type of 'y' defaults to 'int' [-Wimplicit-int]
main.c:1:36: error: 'n' undeclared (first use in this function)
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      |                                    ^
main.c:1:36: note: each undeclared identifier is reported only once for each function it appears in
main.c: At top level:
main.c:1:50: error: return type defaults to 'int' [-Wimplicit-int]
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      |                                                  ^~~~
main.c: In function 'main':
main.c:1:50: error: type of 'n' defaults to 'int' [-Wimplicit-int]
main.c:1:63: error: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      |                                                               ^~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'scanf'
  +++ |+#include <stdio.h>
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
main.c:1:63: warning: incompatible implicit declaration of built-in function 'scanf' [-Wbuiltin-declaration-mismatch]
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      |                                                               ^~~~~
main.c:1:63: note: include '<stdio.h>' or provide a declaration of 'scanf'
main.c:1:102: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    1 | a,b,i,t;long long k=1;L(x,y){!y?k*=n/x:L(y,x%y);}main(n){for(;scanf("%d%d",&a,&b)*a;L(n,k),n=++i%3<1?printf("%lld\n",k),k=1:1)for(t=a;t-1;t=t*a%b)++n;}
      |                                                                                                      ^~~~~~
main.c:1:102: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:102: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
main.c:1:102: note: include '<stdio.h>' or provide a declaration of 'printf'