Language: C

v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
}

Compiler output:
main.c:1:1: warning: data definition has no type or storage class
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      | ^
main.c:1:1: error: type defaults to 'int' in declaration of 'v' [-Wimplicit-int]
main.c:1:7: error: type defaults to 'int' in declaration of 'c' [-Wimplicit-int]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |       ^
main.c:1:9: error: type defaults to 'int' in declaration of 'p' [-Wimplicit-int]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |         ^
main.c:1:11: error: return type defaults to 'int' [-Wimplicit-int]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |           ^
main.c: In function 'f':
main.c:1:11: error: type of 'X' defaults to 'int' [-Wimplicit-int]
main.c:1:47: error: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                               ^~~~~~
main.c:1:1: note: include '<stdio.h>' or provide a declaration of 'printf'
  +++ |+#include <stdio.h>
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
main.c:1:47: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                               ^~~~~~
main.c:1:47: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c: At top level:
main.c:1:66: error: return type defaults to 'int' [-Wimplicit-int]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                                                  ^~~~
main.c: In function 'main':
main.c:1:66: error: type of 'n' defaults to 'int' [-Wimplicit-int]
main.c:1:78: error: 's' undeclared (first use in this function)
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                                                              ^
main.c:1:78: note: each undeclared identifier is reported only once for each function it appears in
main.c:1:84: error: implicit declaration of function 'atoi' [-Wimplicit-function-declaration]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                                                                    ^~~~
main.c:1:89: error: implicit declaration of function 'gets' [-Wimplicit-function-declaration]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                                                                         ^~~~
main.c:1:98: warning: incompatible implicit declaration of built-in function 'printf' [-Wbuiltin-declaration-mismatch]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                                                                                  ^~~~~~
main.c:1:98: note: include '<stdio.h>' or provide a declaration of 'printf'
main.c:1:137: error: implicit declaration of function 'strlen' [-Wimplicit-function-declaration]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                                                                                                                         ^~~~~~
main.c:1:1: note: include '<string.h>' or provide a declaration of 'strlen'
  +++ |+#include <string.h>
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
main.c:1:137: warning: incompatible implicit declaration of built-in function 'strlen' [-Wbuiltin-declaration-mismatch]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                                                                                                                         ^~~~~~
main.c:1:137: note: include '<string.h>' or provide a declaration of 'strlen'
main.c:1:144: error: passing argument 1 of 'strlen' makes pointer from integer without a cast [-Wint-conversion]
    1 | v[50],c,p;f(X){for(;c<X;c+=v[p++]);c=50*(c-X);printf(":%d\n",c);}main(n){for(s;c=n=atoi(gets(v));printf("%d\n",s)){for(p=s=0;p<n;v[++p]=strlen(gets(v+n)));for(;c;)c=0,p=++s,f(5),f(7),f(5),f(7),f(7);}
      |                                                                                                                                                ^~~~~~~~~
      |                                                                                                                                                |
      |                                                                                                                                                int
main.c:1:144: note: expected 'const char *' but argument is of type 'int'